Resorbable porous ceramics derived from chemically converted corals have been used successfully as bone graft substitutes for many years. Converted corals provide a 3D porous architecture that resembles cancellous bone with a pore diameter of 200–700 μm. The success of these corals as a bone graft substitute relies on vascular ingrowth, differentiation of osteoprogenitor cells, remodelling and graft resorption occurring together with host bone ingrowth into the porous microstructure or voids left behind during resorption. The resorption rate of the coral can be controlled by partial conversion to provide a hydroxyapatite (HA) layer via thermal modification. This study examined the resorption rates and bone formation of partially converted corals in a bilateral metaphyseal defect model.

Bilateral defects (5 mm x 15 mm) were created 3 mm below the joint line in the proximal tibia of 41 skeletally mature New Zealand white rabbits following ethical approval. Two variations of a calcium carbonate–HA coral (Pro Osteon 200 R, Interpore-Cross International, Irvine, CA) were examined with different HA thickness (200R; 14% or 200 RT; 28%). Empty defects (negative control) or defects filled with morcellised bone autograft from the defect sites (positive control) were performed. The tibiae were harvested at 6, 12, 24, 36 or 52 weeks, radiographed (standard x-rays and faxitron) in the anteroposterior and lateral planes. Tibias were processed for torsional testing and quantitative histomorphometry using back scattering scanning electron microscopy. Four additional rabbits were killed at time zero to determine the mechanical properties of the intact tibia (n=6 tibias) and 2 for tibias for time zero histomorphometry. Data were analysed using a 3-way analysis of variance.

No clinical complications were encountered in this study. Radiographic assessment revealed a progression in healing, implant resorption and bone infiltration. Cortical closure in the 200 R and 200RT treated defects was noted by 24 weeks. All specimens failed in torsional testing with a spiral fracture initiating at the distal defect site and extending into the distal diaphysis. Torsional properties reached intact control tibia levels by 24 weeks in both groups. No significant differences were noted between 200 R and 200 RT based on torsional data. SEM revealed progressive resorption of the calcium carbonate core of the 200 R and 200 RT with time, infiltration of bone and ingrowth to the HA layers. Time and measurement site (cortical versus cancellous) were significant for implant resorption, bone, and void. The thinner HA layer (200 R) resorbed more quickly compared to the thicker layer (200 RT) in the canal as well as cortical sites. Increased bone and decreased void were noted at the cortex measurement sites in the 200 R group at 24 weeks and in the 200 RT group at 12 and 24 weeks (p< 0.05). Implants were nearly completely resorbed by 52 weeks with only a few percent of implant remaining.

Chondromodulin-I (ChM-I) is a bifunctional autocrine regulator of cartilage, initially isolated from fetal bovine epiphyseal cartilage¹. ChM-I stimulates matrix synthesis of chondrocytes, but inhibits the growth of endothelial cells^1,2 thus ChM-I may be one of the anti-angiogenic molecules present in cartilage. In fetal bovine bone, ChM-I was expressed by all epiphyseal and growth plate chondrocytes except hypertrophic chondrocytes and was present in the matrix throughout the epiphysis and the growth plate, except the hypertrophic zone ^2,3, consistent with its proposed role as anti-angiogenic factor. To examine the possible role of chondromodulin-I in relation to angiogenesis at the vascular front, we studied the immunolocalisation in femoral growth plates from young and mature rats (2–16 weeks) as well as aged rats (62–80 weeks), using a rabbit polyclonal antibody raised against the entire region of mature human recombinant ChM-I.

In 2-week old rats, ChM-I was synthesised by all epiphyseal chondrocytes and strong immunostaining was found in the matrix. In the growth plates, ChM-I staining was present in chondrocytes and matrix of the reserve, proliferating and maturing zones with loss of staining in the hypertrophic zone. However, ChM-I was also present where cartilage canals had penetrated into the chondroepiphysis. In 4–16 week old rats, there was a progressive change in the localisation of ChM-I. Hypertrophic chondrocytes also became positive for ChM-I, while cellular staining gradually disappeared from the other zones. By 12–16 weeks, very strong immunostaining was present almost exclusively on the inner perimeter of the lacunae of hypertrophic chondrocytes. As lacunae were opened at the vascular front, ChM-I initially remained on the cartilage-side of the lacunae, and then disappeared completely. In aged rats, very little ChM-I was present in the cells and matrix of the growth plates, except where remodelling had occurred or chondrocytes had become re-activated.

The rate of longitudinal growth in rats is high between 1–5 weeks, then declines until skeletal maturity at approximately 12 weeks, after which a very slow rate of growth continues until 26 weeks. In young rats, the loss of ChM-I in the hypertrophic zone was as expected for an anti-angiogenic factor, i.e. loss was required before vascular invasion could take place. However, the same did not apply to cartilage canal formation, since there was no loss of ChM-I around cartilage canals. The change in the localisation of ChM-I in mature rats, in particular the very intense immunolocalisation around hypertrophic chondrocytes, might be related to the reduced rate of growth. It is possible that rapid vascular invasion must be slowed down in these growth plates and that ChM-I prevented vascular invasion until degraded by proteases, such as MMP-9.

The relative absence of ChM-I in the stationary growth plates of aged rats suggests that other anti-angiogenic factors prevent vascular invasion in these growth plates.

Osteoblast progenitor cells can be isolated from human bone marrow and on an appropriate carrier following differentiation into osteoblasts a bone block could be formed. This supply of autologous, osteoinductive bone graft substitute would have significant implications for clinical use. The aim of the study was to assess whether osteoblast progenitor cells isolated from human bone marrow, seeded onto porous hydroxyapatite (HA) blocks adhere, proliferate and differentiate into osteoblasts under the influence of HA alone.

After informed consent, bone marrow was aspirated from the iliac crest of 8 patients. The osteoblast progenitor cells were separated from the haematological cells and cultured in vitro. Evidence for the osteoblast progenitor nature of the cells was obtained by adding osteogenic supplements: dexamethasone, ascorbic acid and b-glycophosphate, and comparing alkaline phosphatase (ALP) and osteocalcin expression with that of unstimulated cells. Undifferentiated osteoblast progenitor cells were seeded at a density of 2x10 ⁶ cells/porous HA cylindrical block (8 x 8 x10 mm). The cell adhesion to the HA was observed, and proliferation and ALP expression was measured over 15 days.

In monolayer culture the isolated bone marrow cells were morphologically identified as mesenchymal stem cells. When osteogenic supplements were added the phenotype became consistent with the morphology of osteoblastic cells, and the ALP expression was significantly higher (P< 0.05) after 5 days in culture compared with cells that had not been stimulated to differentiate.

On the HA osteoblast progenitor cells were adherent and became more osteoblastic, being separated from the HA surface by an osteoid matrix layer on electron microscopy. The ALP expression by these cells increased significantly (P< 0.05) over the 15 day culture period.

Bone marrow contains mesenchymal stem cells with osteogenic potential that are known as osteoblast progenitor cells. In this study we have shown that osteoblast progenitor cells can be isolated from human bone marrow and will adhere to and proliferate on HA blocks in vitro, and differentiate into osteoblasts spontaneously under the influence of the HA scaffold. These constructs could be used as osteoinductive bone grafts.

Deep infection is a devastating complication of total joint arthroplasty. In a significant proportion of cases it remains a diagnostic challenge. Haematological tests are not specific, particularly in chronic cases, and radiological investigations such as bone scan and radiographs are of only limited value. The most common infective organisms are staphylococcus and some streptococcus species. Acidity is a well established occurrence in infective processes and is caused by the direct production of acid by the organism or by enzymatic degradation of tissues ^1,2. In wound infections, peritonitis and some other conditions pH is used as an indicator of infection in clinical practice³. The aim was to assess whether fluid biochemistry (pH, pCO2, pO2, Lactate and Glucose) is altered in infected total knee replacements and whether it could be used as a diagnostic test.

Nineteen consecutive patients undergoing either revision total knee replacement (TKR) or arthroscopic synovial biopsy were included in the study. All had had their primary joint replacement within the previous 3 years. All had a painful total knee replacement and some had evidence of loosening of the prosthesis on radiological investigations. The following investigations were performed on each patient, White cell count (WCC), Erythrocyte Sedimentation Rate (ESR), C-Reactive Protein (CRP), interface synovial biopsy for histology and microbiology and a synovial fluid aspiration from the affected joint prior to application of a tourniquet. A blood gas analyser was used to measure pH, pCO2, pO2, Lactate and Glucose in all synovial fluid specimens.

Seven patients were diagnosed as having an infected TKR on clinical and laboratory investigations. The mean synovial fluid biochemistry results were pH = 7.09, pO2= 5.08kPa, pCO2=10.40kPa, Lactate = 5.33 mmol/l, Glucose = 2.30 mmol/l. In the non-infected group the results were pH = 7.23, pO2 = 7.72kPa, pCO2 = 8.41kPa, Lactate = 4.03 mmol/l, Glucose = 3.42 mmol/l. The differences in pH, pCO2/pO2 ratio, and glucose levels were statistically significant (t-Test p < 0.05) between the two groups. Lactate levels were not significantly different. There was no correlation between high WCC’s and synovial fluid biochemistry or laboratory results for infected cases. Using laboratory results as a gold standard and a synovial fluid pH of less than 7.20, the sensitivity was 85% and specificity 77% for diagnosing an infection. Using a combination of the synovial fluid biochemistry results these values were greater.

Synovial fluid biochemistry is significantly altered in infected total knee replacements. pH levels below 7.2, pCO2/pO2 ratio above 2.5 and Glucose levels below 2.5 mmol/l are strong indicators of an infected TKR. Synovial pH assessment may prove to be a quick, cheap and effective method of diagnosing an infected TKR and may also apply to other joints. Further studies using non-problematic TKR’s as controls are required.

Ex vivo gene transfer of osteogenic factors into multipotential stem cells offers potentially important therapeutic implications in a variety of musculoskeletal diseases. One possible approach is the development of a cellular vehicle, namely bone morphogenetic protein (BMP)-producing bone marrow cells, created using adenoviral gene transfer. These transduced cells provide local delivery of BMP for bone formation. The aims of this study were to study the feasibility of gene transfer to human bone osteoprogenitor cells, using adenoviral vectors. Specifically, the aims were to study the efficacy of transduction with an adenoviral vector expressing BMP-2 and then to determine the ability of the transduced cells to produce active BMP-2 and to generate bone ex vivo.

Primary human bone marrow osteoprogenitor cells were expanded in culture and infected with AxCALacZ, a replication-deficient adenoviral vector carrying the E. coli lacZ gene, with a range of multiplicity of infection (MOI) of 6.25 to100. Transduced cells showed positive staining for β-galactosidase using X-Gal with an efficiency close to 100%. Uninfected cells showed no β-galactosidase activity. Efficiency was independent from MOI, however cells infected at the lower MOIs expressed lower levels of β-galactosidase. Following confirmation that primary bone marrow cells could be infected by adenoviral constructs, additional osteoprogenitors were infected with AxCAOBMP-2, a vector carrying the human BMP-2 gene, at a multiplicity of infection of 10–20. In order to determine BMP-2 activity, conditioned media from bone marrow cells expressing BMP-2 was added to promyoblast C₂C₁₂ cells. The promyoblast C₂C₁₂ cells are exquisitely sensitive to BMP-2 with induction of alkaline phosphatase activity (ED₅₀ 20 nM) in a dose-dependant manner. Alkaline phosphatase activity was induced following culture with conditioned media from BMP-2 expressing cells, in a dose dependant manner, confirming successful secretion of active BMP-2. Immunohistochemical staining for alka- line phosphatase in C₂C₁₂ cells also confirmed the bio-chemical observations. Media from uninfected control human bone marrow cells failed to produce a similar effect. The concentration of BMP-2 in the media was estimated to be 5–10 nM/10⁷ cells.

To examine whether adenoviral transfection affected the osteoblast phenotype and their ability to mineralise in vitro, adenovirally-transduced bone marrow cells expressing BMP-2 were seeded onto poly(-lactic acid co÷glycolic acid) (75:25) porous scaffolds (provided by K. Shakesheff and S. Howdle; Nottingham University) and cultured for up to 6 weeks. Expression of alkaline phosphatase activity, type I collagen formation, as well as the synthesis of osteoblast stimulating factor-1 confirmed bone cell differentiation and maintenance of the osteoblast phenotype in extended culture for up to 6 weeks.

These results indicate the ability to deliver active BMP-2 using human bone marrow osteoprogenitor cells following adenoviral infection. The maintenance of osteoblast phenotype in extended culture and generation of mineralised 3-D scaffolds containing such constructs offers a realistic approach to tissue engineer bone for orthopaedic applications.

Detection of infection in total joint replacements (TJR) is notoriously difficult. Ideally the diagnosis should be known before revision arthroplasty is undertaken. The level of C-reactive protein (CRP) is one readily available test. Sanzen et al. reported sensitivity of 78% and specificity of 100% for CRP in distinguishing infection in 23 infected TJRs and 33 non-infected TJRs undergoing revision, using a cut off of 2mg/dl¹. However, they used only intra-operative cultures as the standard to compare the CRP against. We have analysed the reliability of CRP to diagnose infection pre-operatively in a group of patients undergoing revision arthroplasty, using the following criteria as the reference standard for infection: 2 or more intra-operative cultures positive for the same organism; presence of acute inflammatory response on histology; presence of pus in the joint at revision (1/3 positive indicates true infection), as described by Hanssen et al.²

The results of CRP and the operative investigations of 26 patients undergoing revision arthroplasty (15 hips and 11 knees) were studied prospectively. In our unit CRP is assayed in mg/dl serum by an automated machine. During revision arthroplasty, multiple specimens were taken from around the joint for microbiological and histological examination. Microbiological cultures were carried out on solid media and broth in aerobic and anaerobic conditions. Histological analysis assessed the level of neutrophils present in the tissue. The presence or absence of pus was noted. The results were analysed graphically and a cut off level of CRP was then chosen for analysis of reliability.

Thirteen patients were infected and 13 were not. Eleven of the 13 infected patients had a CRP greater than 2 mg/dl, and 10 of the 13 non-infected patients had a CRP less than 2 mg/dl. Using 2 mg/dl as a cut off, CRP had a sensitivity of 85% and a specificity of 77%. If 4mg/dl is taken as the threshold for infection, then CRP is 100% specific but only 61% sensitive.

CRP is a useful investigation in the diagnosis of infection in joint replacements. However we have shown that a cut off of 2mg/dl is not 100% specific for non-infected patients. Increasing the threshold improves the specificity, but reduces the sensitivity. Unfortunately there is no single investigation that is 100% accurate in this setting. CRP results must be interpreted in the light of the clinical picture and other investigations. These patients are part of an ongoing study to identify the most reliable criteria for diagnosing the presence of infection in total joint replacement.

The formation of biomimetic environments using scaffolds containing cell recognition sequence and osteo-inductive factors in combination with bone cells offers tremendous potential for bone and cartilage regeneration. In tissues, collagen forms the scaffold by mediating the flux of chemical and mechanical stimuli. Recently, a synthetic 15-residue peptide P-15, related biologically to the active domain of type I collagen, has been found to promote attachment and the osteoblast phenotype of human dermal fibroblasts and periodontal ligament fibroblasts on particulate anorganic bone mineral (ABM). The aim of this study was to exam the ability of the collagen peptide, P-15, to promote human osteoprogenitor attachment, proliferation and differentiation on cell culture surfaces and 3-D scaffolds.

Selected human bone marrow cells were cultured on particulate microporous anorganic bone mineral (‘pure ‘ hydroxyapatite based on x-ray diffraction standard JCPDS9-432) phase and polygalactin vicryl mesh adsorbed with or without P-15 in basal or osteogenic conditions. Cell adhesion, spreading and patterning were examined by light and confocal microscopy following incorporation of cell tracker green and ethidium homodimer fluorescent labels. Osteoprogenitor proliferation and differentiation was assessed by DNA content and alkaline phosphatase specific activity. Growth and differentiation on 3-D ABM structures were examined by confocal and scanning electron microscopy (SEM).

P-15 promoted human osteoprogenitor cell attachment and patterning on particulate bovine anorganic bone mineral phase and polygalactin vicryl mesh over 5–24 hours compared to culture on ABM and vicryl mesh alone as observed by photomicroscopy. Increased alkaline phosphatase specific activity was enhanced following culture on P-15 adsorbed matrices as recognized by enhanced expression of alkaline phosphatase, type I collagen, osteocalcin and cfba-1. The presence of mineralised bone matrix and extensive cell ingrowth and cellular bridging between 3-D ABM matrices and polygalactin vicryl mesh adsorbed with P-15 was observed by confocal microscopy and alizarin red staining. SEM confirmed the 3-D structure of newly formed cell constructs and cellular ingrowth on and between the P-15 modified inorganic bone mineral materials. Negligible cell growth was observed on ABM alone or polygalactin vicryl mesh alone.

These observations demonstrate that the synthetic 15-residue collagen peptide, P-15, when adsorbed to ABM or polygalactin vicryl mesh, can stimulate human osteoprogenitor attachment and spreading. They also demonstrated that P-15 coupled 3-D matrices stimulate human osteoprogenitor differentiation and materialisation. The studies indicate that a synthetic analogue of collagen provides a biomimetic environment supportive for cell differentiation and tissue regeneration and indicate a potential for the use of extracellular matrix cue in the development of biomimetic environments for bone tissue engineering.

Pre-revision detection of infection in failed total joint replacements (TJR) is essential to allow appropriate management planning. Unfortunately, low-grade infection is often difficult to detect. The use of molecular biology may offer increased sensitivity in this setting. We have analysed the use of the Polymerase Chain Reaction (PCR) to diagnose infection in pre-operative aspirates in a group of patients undergoing revision arthroplasty. We prospectively tested 50 aspirates in 50 patients with failed TJR (34 hips and 16 knees). Antibiotics were omitted for 2 weeks prior to aspiration. The aspirate was sent for microbiological culture in aerobic and anaerobic conditions. An aliquot was retained for PCR analysis which involved DNA extraction then amplification of an 882 base pair segment of the Universal 16S RNA gene. In 33 patients who subsequently underwent revision arthroplasty multiple specimens were taken from around the joint for microbiological and histological examination and the presence or absence of pus was noted. The patient was deemed to be infected if one of these criteria was found: 2 or more intra-operative cultures positive for the same organism; an acute inflammatory response on histology; pus in the joint at revision ¹.

PCR was positive in 29 cases. Aspiration microbiology was positive in 13 cases. Of the 33 cases revised, 15 patients were deemed to be infected using the previously established criteria, described above. Compared to preoperative aspiration microbiology PCR had a sensitivity of 92% and specificity of 54%. Compared to the published criteria for infection, PCR was 93% sensitive and 61% specific. If rheumatoid cases are excluded the specificity improves to 71%.

It was concluded that PCR has the ability to amplify very small amounts of target DNA. The apparently high false positive rate compared to aspiration microbiology may indicate that PCR is picking up DNA from contaminating or non-viable organisms (treated or phagocytosed), giving poor specificity. However, microbiology is known to have poor sensitivity on pre-operative aspiration samples, and some of the microbiology results may be false negative. Compared to the criteria for infection after revision our results for PCR are more encouraging, especially for non-rheumatoid patients. These patients are part of an ongoing study to identify the most reliable criteria for pre-operative diagnosis of infection in total joint replacement.

Most infections in arthroplasty are caused by staphylococci, about half being due to S. aureus. One of the most worrying aspects of this organism, and particularly of MRSA, is increasing multiple drug resistance, so that antimicrobial prophylaxis is probably already compromised. Vaccination offers a novel approach to overcome this. Detailed consideration of the pathogenesis of prosthesis–related infection indicates that a) prosthetic material rapidly becomes coated after implantation with plasma–derived conditioning film, and b) attachment of the bacteria to the conditioning film, by means of specific bacterial surface binding proteins, is an essential primary event. We hypothesise that antibodies to these binding proteins will block bacterial adhesion to the prosthesis, so reducing the incidence of infection. The aim of this research was to determine the effect of specific antibodies to two binding proteins (fibronectin - and fibrinogen–binding proteins, Fnbp and Fgbp respectively) on bacterial adherence to orthopaedic biomaterials coated with plasma conditioning film.

Antibodies to recombinant sequences of Fnbp and Fgbp were raised in rabbits. A strain of S. aureus bearing a genetically inserted fluorescent reporter (GFP) was used. Orthopaedic biomaterials (steel, titanium and PMMA) were coated with FFP–derived conditioning film, placed in a specially–designed flow cell and exposed to a flow of S. aureus for 3h. Images were captured every 15min and analysed for adherent bacteria using image analysis software. The experiment was repeated in the presence of the antibodies and the results compared.

Each antibody reduced the number of bacteria binding to all three materials by greater than 50%. Combining the two antibodies gave similar results to those when they were used individually.

These preliminary results suggest that while further research is required, vaccination aimed at blocking bacterial attachment to conditioning film on implanted prostheses might reduce the incidence of S. aureus infection in arthroplasty. If so, this would apply even to MRSA. Questions remaining to be addressed include the clinical relevance of a 50% reduction in attachment, and future research will attempt to link this to a reduction in infection.

Fracture repair is a complex physiological process during which bone shows the remarkable ability to mount a repair process, restoring its mechanical integrity and anatomical configuration by original osseous tissue. Programmed cell death, or apoptosis, is a naturally occurring cell suicide pathway with a homeostatic function in the maintenance of continuously renewing tissues. The present study investigated the relation between cell proliferation and cell death (apoptosis) during fracture healing in a mouse femoral model.

Left femoral osteotomies were performed in 20 male CFLP mice (35–45g), immobilised with uniplanar external fixators. 4 animals were sacrificed on days 2, 4, 8, 16 and 24 post-fracture and fracture callus collected for paraffin embedding. Localisation of cell proliferation was examined using immunohistochemistry with proliferating cell nuclear antigen (PCNA) monoclonal antibody. Apoptotic cells were visualised with the terminal deoxynucleotidyl transferase (TdT)–mediated dUTP-biotin nick end-labelling (TUNEL) method. Random images of each time specific specimen were captured via a digital camera and the positive labelling indices of PCNA and TUNEL labelling were calculated and statically compared.

Cell proliferation and apoptosis were found co-existing during the entire period of fracture healing studied. Cell proliferation was predominant in the early phases of fracture healing (days 2–8). PCNA positive labelling index peaked at day 8 (p< 0.01, t-test) and PCNA-positive cells were not limited to the fracture gap mesenchymal tissues but extended in the periosteum along most of the fractured femur. TUNEL positive labelling was minimal in the early stages (days 2–8). In later stages of fracture healing (days 16–24), PCNA expression declined as intramembranous and endochondral ossification spread within the fracture site and apoptosis was the dominant cell activity with the TUNEL positive labelling index peaked at day 16 (p< 0.05, t-test) and then declined sharply at day 24.

The current study indicated that apoptosis was a normal concomitant during fracture repair, confirming programmed cell death in chondrocytes and bone cells, and that cell proliferation and apoptosis were tempero-spatially dependent. These findings support the view that apoptosis is a natural process, genetically programmed and active during fracture repair. The demonstration of a mixture of proliferative and apoptotic cell populations in the regenerating tissues of fracture callus, suggests that apoptosis and cell proliferation may be regulated by local factors during fracture healing.

Metallic implants are used frequently in the operative repair of joints and fractures in orthopaedic surgery. Metal infection is a catastrophic complication of the surgery with patients loosing their newfound mobility and independence, associated morbidity and mortality is high. Orthopaedic implant infection is chronic and biofilm based. Present treatment focuses on removing the infective substratum and implant surgically as well as prolonged anti-microbial therapy. Biofilms are 500 times more resistant than planktonic strains of bacterial flora to antibiotics, and with evolving resistant strains this form of therapy is loosing ground. Silver coatings on polymers and nylon (catheters, heart valve cuffs, burn dressings) have shown inhibition of this biofilm formation in its adhesion stage. Our aim was to deposit effective, minute, biocompatible, anti-bacterial layers of silver on orthopaedic stainless steel K-wires.

Combining magnetron sputtering with a neutral atom beam (Saddle Field) plasma source at 10⁻⁴ mbar in argon gas at temperatures of 60°C, a silver coating of 99.9% purity was deposited onto stainless steel orthopaedic K-wires. Coating thickness measurements were obtained using glancing angle x-ray diffraction of glass slides coated adjacent to wires. Magnetron parameters were modified to produce varying thickness of silver. Adhesiveness was examined using Rockwell punch tests and tape tests. Silver leaching experiments were carried out in phosphate buffered saline at 37°C for 48hrs and using inductive coupled plasma spectrometry to assess leached silver ions. Surface microscopy visualised physical changes in the coatings. Biofilm adhesion was determined by exposing wires to Staphylococcus aureus ATCC 29213 -NCTC 12973 for 15 min to allow biofilm adhesion and initiation. Wires were then cultured for 24h at 37°C in RPMI. Subsequently wires were sonicated at 50Hz in ringer’s solution and gently vortexed to dislodge biofilm. Sonicate was plated by the log dilution method on blood agar plates. Bacterial colonies were then counted and changes expressed in log factors. Surface biofilms were visualised using scanning electron microscopy. Cytotoxicity was assessed using fibroblast cell cultures lines.

K-wires were coated with 5 to 50 nm of silver by running the magnetron sputtering at low currents. These coatings showed excellent adhesive properties within the 48hr exposed with only 5% of silver leaching in buffered saline. The silver coated wires showed a log 3–4 fold reduction in biofilm formation as compared to control wires. The coatings showed no cytotoxic effects.

Silver coating of medical implants has been shown in urological catheters to reduce biofilm infection. We have perfected a method of depositing thin layers of anti-bacterial silver onto stainless steel, which is both anti-infective and biocompatible. This coating could potentially add to the armourary of anti-infective agents in the elimination of infection related orthopaedic implant failure.

During the process of distraction osteogenesis new bone is formed rapidly and undergoes remodelling almost immediately. Little is known about the regulatory mechanisms governing the removal of the redundant callus in this process. Tissue homeostasis is achieved by a delicate balance between the processes of cell death (apoptosis) and cell proliferation. The aim of this study was to test the hypothesis that apoptosis is involved during distraction osteogenesis.

Mid-tibial osteotomies were performed in 6 adult male NZW rabbits (age; 24 weeks, weight; 3.0 −3.5 kg), and the tibiae stabilised with unilateral external fixators (Orthofix M-100). 7 days later, twice daily distraction was initiated at rates of 0.7 mm/day for 3 weeks. BrdUrd (40mg/kg) was injected intravenously to the rabbit 1h before killing. The regenerate bone was collected, fixed in 10% buffered formalin and decalcified for paraffin embedding. Some fresh regenerate bone tissues were also prepared for examination under transmission electronic microscopy (TEM). BrdUrd immunohistochemistry has been used to detect proliferating cells and the terminal deoxynucleotidyl transferase (TDT)-mediated dUTP-biotin nick end-labelling (TUNEL) method was used to identify cells undergoing apoptosis. To detect bone-resorbing cells, tartrate-resistant acid phosphatase (TRAP) staining was also performed.

BrdUrd positive cells and TUNEL-positive cells were shown to coexist in most of the areas in the regenerates. In the mineralisation front, the majority of the TUNEL-positive cells were present in the transitional region between the fibrous tissue and the new bone. The TUNEL-positive cells were close to or on bone surfaces, and some of the newly formed osteocytes in the new trabeculae were also positive. The TUNEL-positive cells were also seen in the cartilage region of the regenerate. However, the TUNEL labelling was greatly reduced in the new bone close to the osteotomised bone ends, TUNEL-positive labelling were not detected in the cortical bone of the osteotomised bone ends and in the adjacent surrounding periosteum. TRAP staining in the regenerate revealed similar patterns of distribution to those of the TUNEL staining. There were more TRAP-positive cells in the new bone near the mineralisation front than in that of the new bone region, which was close to the osteotomised bone ends. TEM examinations have demonstrated characteristic signs of apoptotic changes in the fibroblast, osteoblast and osteocytes in the specific regions of the distraction regenerate.

The study provided evidence that in the process of rapid bone formation during distraction osteogenesis, superfluous cells are removed by apoptotic mechanisms. The demonstration of a mixture of proliferative and apoptotic cell populations in the regenerating tissue, indicates that apoptosis and cell proliferation may be regulated by local factors. The neovascularisation of the regenerate and withdrawal of growth factors and cytokines may be responsible for apoptosis occurring in some parts of the regenerating tissue. The changes of distribution of apoptotic cells in the different regions of the regenerate, together with the observed patterns of osteoclast activities, suggest that bone cells undergoing apoptosis may initiate rapid bone remodelling seen during distraction osteogenesis.

Atrophic non-unions are usually attributed to impaired blood supply but the events that lead to atrophic non-union remain poorly understood. Recent studies^1,2 have shown that vascularity is not reduced in established non-unions but these studies have not examined vascularity at an early stage. The aims of this study were to: 1) develop and validate a clinically relevant small animal model of atrophic non-union and 2) test the hypothesis that the vessel density of atrophic non-unions reaches that of normal healing bones but at a later time point.

Twenty eight adult female Wistar rats underwent application of a novel circular frame external fixator to the right tibia under general anaesthesia. The fixator construct was standardised, with eight needles that were drilled through the skin into the proximal and distal metaphyses of the tibia. An osteotomy was performed with a 1mm burr under irrigation. The periosteum was removed on 14 of the 28 animals using a scalpel and the intramedullary canal was curetted. Both insults were performed proximally and distally for a distance equivalent to 1 diameter of the tibia. A 1mm gap was introduced at the osteotomy site and the wound was closed. Once the animal had recovered it was allowed unrestricted weight bearing. Anteroposterior X rays were performed every 2 weeks. Animals were killed at 1, 3, 8 and 16 weeks. Callus areas were measured from X rays using an image analysis system. The average callus area was calculated for each rat every 2 weeks as an indicator of callus production. Specimens were fixed, decalcified, embedded in paraffin wax and 6 ìm sections were stained with H& E. Vascularity was assessed immunohistochemically with monoclonal antibody against smooth muscle actin. The total number of blood vessels in the interfragmentary gap was counted.

At 8 and 16 weeks post-osteotomy all animals where stripping and curetting had been performed went on to an atrophic non-union. All animals where this was not performed went on to unite successfully. Histological observations support these radiological findings. Significantly less callus formed in the non-unions than in those that united. There were significantly fewer vessels in the non-unions at week 1 compared to the controls but, by 8 weeks the blood vessel density in the established atrophic non-unions had reached the same level as the vessel density during normal healing.

An atrophic non-union model that closely resembles the clinical situation has been developed and validated in rats. The results support the hypothesis that the number of vessels in atrophic non-unions reaches the same level as in those that unite but at a later time point. It is concluded that diminished vessel density within the first 3 weeks may prevent fractures from uniting.

Fracture healing involves many local and systemic regulatory factors. Progress in identifying signaling events downstream has been made with the discovery of a novel family of proteins, the Smad, as TGF-ß/activins/BMPs signal transducers. Smads are the vertebrate homologs of Mad (Mothers against decapentaplegic) gene from Drosophila and Sma genes from Caenorhabditis elegans. Smad-1, -2, -3, -5, -8 and -9 belong to the receptor-regulated class (R-Smad) which are activated by the TGF-ß type I and II receptors, forming heteromers with the common-mediator class (Co-Smad): Smad-4. Smad-6 and -7 (Anti-Smad) perform a negative regulatory or balancing role. Smad-2 and -3 regulate TGF-ß/activin effects, whilst Smad-1 and -5 work with BMPs. This study investigated the expression and localization of Smad proteins (Smad 1–6) and BMP-4 and -7 during fracture healing.

Eighteen 3-month old female CD-COB rats were used. A standard closed fracture was made in the mid-shaft of right femur using a 3-point bending device. The left limb served as the non-fracture control. The rats were divided into 3 groups (6 per group) and sacrificed at day 3, 10 and 28 after fracture. The femurs were harvested, fixed in buffered formalin for 48 hours and decalcified with 10% formic acid-formalin solution. The decalcified tissues were embedded in paraffin and 5μm sections were cut onto silane-coated slides. Representative slides from each block were stained with routine haematoxylin and eosin (H& E). Sections were cut for immunohistochemistry for protein marker expression by a standard procedure for Smads and BMP 4 and 7. Sections were viewed and analysed by colour video image analysis using a 40x objective, a 10x eyepiece, and a fixed frame of 128 × 128 pixels (49152.0 μm²). Ten fields per slide were examined.

Smad proteins (Smads 1, 4, and 6) were expressed during the early stages (day 3) of fracture healing by bone marrow stromal cells, osteoblasts, fibroblasts and chondrocytes located in the intramembranous and endochondral ossification regions around the fracture site. Differential expressions of individual Smads, particularly Smad 1 and Smad 6, at different time-points (Smad-1 was higher than Smad-6 at day 3, whilst Smad-6 was much higher than Smad-1 at day 10) suggest that Smad proteins are not simply BMP signal transducers. Smads may also be responsible for up- and/or down-regulation of transcriptional events during the intramembranous and endochondral ossification. Smad-4, a Co-SMAD, expression newly formed bone and cartilage suggests an additional function beyond the signal transduction in rat fracture healing. BMP-4 and BMP-7 were highly expressed at day 3 and 10. BMP-7 expression was greater than BMP-4 at day 3 but switched by day 10 (BMP-4 > BMP-7). Smads represent a new level where specific therapeutic strategies can be targeted considering the interactions with a number of BMPs.

Vascular Endothelial Growth Factor (VEGF) has been shown to stimulate angiogenesis in a number of tissues and, in addition, to possess direct vasoactive properties. Stimulation of blood flow and angiogenesis are important features of the fracture healing process, particular in the early phases of healing. Inadequate vascularity has been associated with delayed union after fracture. The periosteum, and in particular its osteogenic cambial layer, has been shown to be very reactive to fracture and to contribute substantially to fracture healing. Fracture haematoma contains a considerable concentration of VEGF and enhanced plasma levels are observed in patients with multiple trauma. VEGF has been suggested to play a role during new bone formation possibly providing an important link between hypertrophic cartilage, angiogenesis and consequent ossification. However, the expression of VEGF in normal periosteum and in periosteum close to a fracture has not been previously reported. We hypothesise that the expression of VEGF in long bone periosteum will show a distinct response to fracture.

We investigated the expression of VEGF in vivo in human periosteum, using immunocytochemistry to detect the expression of Factor VIII and VEGF protein respectively. Under prior approval from the local Ethics Committee, biopsies of periosteal tissues were collected from two distinct groups (1) control and (2) following long bone fracture. Patient age range was 16 – 45 years for both groups. Group 1 consisted of patients (n = 5) who underwent an elective orthopaedic procedure during which periosteum was disrupted. Group 2 patients (n = 8) had long bone fractures from which periosteal tissue was harvested close to the fracture site during internal fixation at various time points following fracture (24 hours to nine days).

In Group 1 the periosteum showed abundant but delicate blood vessels staining throughout for VEGF but there was no other visible staining of other structures or cells. In Group 2 the vasculature in the periosteum close to the fracture site demonstrated a characteristic, time-dependent course of expression of VEGF. At 24 and 48h following fracture the vasculature showed a heterogenous picture. The vessels in periosteum showed signs of activation: thickened endothelia and dilated lumina, but did not express VEGF. At 60h the vessels began to show signs of the presence of VEGF protein and by 4 days most periosteal vessels expressed VEGF. Also at this time, VEGF staining was visible in some of the stromal cells of the periosteum that was not seen in any of the earlier times. At 9 days VEGF was visible not only in the omnipresent vasculature, but now consistently in spindle shaped cells of fibroblastic appearance and chondrocytes throughout the early callus.

This study, though limited by the number of patients, shows for the first time the expression of VEGF in normal periosteum as well as in periosteum during fracture healing. Interestingly, activated vessels in the early healing phase show little expression of VEGF; however it is known that the fracture haematoma contains VEGF in abundance. It is possible that the vasoactive role of VEGF prevails in these early days. There may be a critical time point at around 48h post fracture following which angiogenesis begins and VEGF is expressed in the endothelium throughout the vessel wall. The study suggests an important role for VEGF in the regulation of fracture healing. VEGF is not only expressed in endothelial cells within the periosteum but also in fibroblast-like stem cells and chondrocytes throughout the early callus suggesting it may play an important role in both osteo- and angiogenesis

In rheumatoid arthritis (RA) and other arthritic disorders e.g. gout, there is destruction of articular cartilage and juxta-articular bone. Osteoclasts are specialised multinucleated cells (MNCs) that carry out bone resorption. It has previously been shown that circulating monocytes and synovial macrophages in RA can be stimulated to differentiate into functional osteoclasts in the presence of RANKL and M-CSF. The aim of this study was to determine whether the mononuclear cells present in synovial fluid of RA patients are capable of differentiating into functional osteoclasts in the presence of osteogenic factors.

Mononuclear cells were isolated from the synovial fluid obtained from patients with Ra, osteoarthritis (OA) gout and joint trauma. The cells were seeded onto dentine slices and coverslips and cultured for up to 21 days in the presence/absence of RANKL (30ng/ml) and M-CSF (25ng/ml). Cells cultured on coverslips for 24h, 14 and 21 days were assessed for the expression of the monocyte-macrophage antigen CD14 that is known to be expressed by osteoclasts, and the osteoclast associated markers; tartrate-resistant acid phosphatase (TRAP) and vitronectin receptor (VNR). After 21 days, dentine slices were assessed for evidence of osteoclastic lacunar resorption.

After 24 h culture on coverslips mononuclear cells isolated from the synovial fluid of all the above joint conditions were largely CD14+, and entirely negative for TRAP and VNR. After 14 days culture, in the presence of RANKL and M-CSF these synovial fluid macrophages were stimulated to form multinucleated osteoclasts which were TRAP+ and VNR+ and capable of forming resorption pits on dentine slices. In the absence of either RANKL or M-CSF osteoclast formation did not occur.

The osteogenic factors RANKL and M-CSF have been shown to be present in the synovial fluid of patients with RA, OA, gout and joint trauma. Results from this study demonstrate that CD14+ mononuclear cells (macrophages) in the synovial fluid of patients with the above conditions have the capacity to differentiate into functional multinucleated osteoclasts in the presence of RANKL and M-CSF. These findings show that one cellular mechanisms whereby bone erosions many occur in arthritic disorders is through increased osteoclast formation of synovial fluid macrophages; this process requires RANKL and m-CSF, both of which are produced by inflammatory cells e.g. T Cells found in the synovial fluid and the arthritic synovial membrane.

Tibial fractures represent a heterogeneous group of fractures that are difficult to treat and vary widely in their time to union. Judging when it is safe to remove an external fixator or plaster cast requires clinical and radiological assessments both of which are subjective. Any errors in determining when a fracture has healed can lead to a prolonged treatment time or to refracture. Many methods have been employed to attempt to define clinical union in an objective manner including ultrasound, DEXA scanning, vibration analysis, and fracture stiffness measurements. Stiffness measurements are however time consuming to perform, of debatable clinical significance, and applicable only to fractures treated with external fixators. It has been previously observed^1,2 that weight bearing increases with time post-fracture. It has also been suggested³ that the ability of a patient to weight bear on the fractured limb is controlled by a biofeedback mechanism of biological self-control of fracture site strain that will be related to the stiffness of the fracture. We hypothesised that weight-bearing will be closely related to fracture healing and could be used as an alternative measure of healing where other objective measures of healing are not available or are impracticable.

A group of ten patients with tibial fractures treated by external fixation were studied. Using a Kistler force plate set into the floor, ground reaction forces for both lower limbs (fractured and non-fractured) were measured during normal walking at three weekly intervals. Concurrent fracture stiffness measurements were made using the Orthofix Orthometer.

In 8 patients who made good recoveries, the fixator was removed between 15–20 weeks post injury when the fracture stiffness had reached a minimum of 15 Nm/deg. Weight-bearing through the injured leg was seen to approach 90% of that through the uninjured leg in the 3 weeks prior to fixator removal. Two patients with delayed union achieved weight bearing of less than 40% of normal between 15–20 weeks. They also demonstrated low values of fracture stiffness (< 5 Nm/deg.) and subsequently required operative intervention to achieve union.

In this small study of 10 patients, weight bearing appears to correlate well with clinical union. It is quicker and easier to assess than stiffness and potentially has relevance to other fixation methods. We are continuing these measurements on conservatively treated, intra-medullary nailed, and externally fixed tibial fractures.

The use of intra-articular hyaluronic acid injections for the treatment of early osteoarthritis is in widespread clinical use. Hyaluronate (HA) is a major component of connective tissue¹ and is available commercially for the intra-articular injective treatment of osteoarthritis of the knee and periarthritis of the shoulder. Although it is known to improve intra-articular lubrication it is also thought to promote articular cartilage structure and prevent catabolism of matrix proteoglycans in osteoarthritis. Clinical studies have shown beneficial effects lasting for many months after cessation of therapy unlike anti-inflammatory drugs that have relatively short term relieving effects^2,3 . Documentation of the true chondroprotective effects of hyaluronic acid (HA) at the cellular level is lacking and therefore this study aimed to identify the effects of HA on chondrocytes cultured in vitro.

Bovine articular chondrocytes were isolated by sequential digestion with pronase and collagenase and seeded in 2% alginate at 1x10⁷ cells/ml. The constructs were cultured for up to 14 days in standard culture medium (DMEM + 20% Fetal calf serum) containing varying concentrations of HA (Sigma), including doses equivalent to those found in vivo. The medium was replaced every 3 days and representative constructs were removed from culture, digested and assayed for DNA, glycosaminoglycans and Collagen. Further constructs were fixed in 4% paraformaldehyde for standard histology and immunolocalisation of collagen types I, II and chondroitin-6-sulphate.

Chondrocytes cultured in the HA system proliferated (increase in DNA) at a faster rate than the controls. There was a 2.2 fold increase in cell concentration at 14 days compared to a 1.2 fold increase in the controls. Total GAG levels at each time point were significantly greater for cells cultured in HA than in controls. Histologically, constructs were characterised by extensive cell cluster formation and intense Safranin-O staining. The newly synthesised matrix also stained positive for type II collagen. By contrast, control constructs exhibited minimal cluster formation, Safranin-O and type II collagen staining.

Cells maintained with HA exhibited a significantly greater rate of proliferation and matrix production. The presence of matrix rich in type II collagen indicates maintenance of chondrocytic phenotype. By contrast, cells cultured without HA did not show these features. These results support the use of intra-articular injections for the treatment of osteoarthritis. The benefits of HA injections may be due to cellular mechanisms as well as mechanical.

The use of intra-articular corticosteroid injections for their anti-inflammatory effects is widespread amongst clinicians. Despite their use in both rheumatoid arthritis and osteoarthritis, the effect of these agents on articular chondrocytes is not fully established. Previous reports suggest a detrimental effect on cartilage explants resulting from inhibition of matrix synthesis¹. However it has also been suggested that the beneficial effects in vivo may be due to prevention of inflamed synovium causing cartilage degradation². Our aim was to assess the effect of a commercially available preparation of methylprednisolone (MP), at clinical doses, on articular chondrocytes cultured in vitro.

Bovine articular chondrocytes were isolated by sequential digestion with pronase and collagenase and seeded in 2% alginate at 1x10⁷ cells/ml. The constructs were cultured for up to 15 days in standard culture medium (DMEM + 20% Fetal calf serum) containing varying concentrations of MP, including doses equivalent to those found in vivo. The medium was replaced every 3 days and representative constructs were removed from culture, digested and assayed for DNA and glycosaminoglycans. Further constructs were fixed in 4% paraformaldehyde for standard histology and immunolocalisation of collagen types I, II and chondroitin-6-sulphate.

Chondrocytes cultured in MP containing medium showed a significant abnormality in cell morphology compared to controls at the day 15 time point. Histologically there was evidence of cell necrosis, reduced amounts of extracellular matrix and loss of collagen type II staining. The effects were dose dependant, with significant damage occurring even at clinical doses. Biochemical analysis revealed a reduction in DNA content and an inhibition of glycosaminoglycan and collagen type II synthesis. In contrast, in the controls, there was cell proliferation with a cell doubling time of 14 days, collagen type II containing extracellular matrix synthesis occurred and the chondrocytes maintained their phenotype throughout the culture period.

Methylprednisolone has a significant detrimental effect on cultured articular chondrocytes in vitro. There was significant cell necrosis associated with inhibition of extracellular matrix synthesis. Based on these results, intra-articular corticosteroid injections should be used with extreme caution.

The ACL-deficient knee demonstrates an increase in both tibial rotation and translation that can lead to progressive degeneration within the knee joint. Functional Knee Braces (FKBs) have often been prescribed as an integral part of treatment programmes for such patients. However, the ability of a FKB to increase the stability of the ACL-deficient knee by controlling tibial translation has yet to be confirmed. In addition the athlete with ACL deficiency frequently asks if he/she can use a treadmill as a safe indoor exercise tool.

A prospective study was carried out on 15 pre-operative ACL-deficient patients and 15 fully matched subjects as controls. A gait analysis study was designed using the CODA mpx30 gait analysis system with electromyography (EMGs). The study was carried out using 3 gait situations - simple level walking and treadmill walking (3.6 km/h) both representing low physical activity and treadmill running (10 km/h) representing high physical activity. The tempero-spatial parameters, total range of motion (ROM), joint positions and EMGs were recorded with and without the FKB and the results were compared with the baseline data of both the patients and the data derived from the control subjects.

ACL-deficient subjects had significantly lower speed, shorter stride length and consequently longer double support time while walking on level ground (p< 0.05). None of these variables changed following bracing. The ACL-deficient subjects showed more knee flexion at heel strike and mid-stance which was assumed to be a compensatory reaction to the ligament deficient knee. The FKB significantly reduced ROM in the ACL-deficient subjects at all gait activity levels (p< 0.05). It also reduced peak knee flexion during swing while walking on level ground, but increased maximum knee flexion in swing while walking on the treadmill. Walking on the treadmill reduced hip ROM but running on the treadmill increased ankle ROM in both groups of subjects. No significant angulatory kinematic changes were found during running on the treadmill either before or after bracing. The ACL-deficient subjects showed more knee rotation than the controls during all the trials. Neither the quadriceps nor hamstring muscles showed significant differences between the ACL-deficient and control subjects. The gastrocnemius muscle however was found to have a principal role in the ACL-deficient subjects. FKBs caused the gastrocnemius to be activated earlier (P=0.0001) and showed a positive effect during low force activities. As treadmill walking or running was always accompanied by an increased ankle plantar flexion, it always decreased the gastrocnemius onset activation time that may be a compensatory reaction to stabilise the injured knee. No significant differences were found between the ACL-deficient and the control subjects in terms of kinematics or EMG findings during running on the treadmill.

We have identified beneficial biomechanical changes following the use of FKBs on ACL-deficient knees but only during walking trials. The brace was as effective for walking on the treadmill as walking on the ground. The FKBs led the deficient knees into a safer kinematics and EMG pattern. The ACL-deficient subjects ran as normally as the control subjects and no effects of the FKBs were found during running in our studies.

The aim of this study was to determine the function of the meniscofemoral ligament in the cranio-caudal and rotatory laxity of the ovine stifle.

Twenty fresh cadaveric ovine stifles were harvested from fully mature sheep, average weight 25kg. The joint was denuded of its muscular attachments leaving the capsule, including the patella and patellar tendon undisturbed. The femur and tibia were divided 10 cm from the joint line, positioned in cylindrical pots, and secured in polymethylmethacrylate bone cement. The stifles were tested in a four-degree-of-freedom rig positioned in an Instron materials testing machine. This allowed unconstrained coupled tibial rotations and translations during application of cranial (anterior) and caudal (posterior) draw forces. Forces up to a maximum of 100Nm were applied in the anterior and posterior directions, and the resultant translations were measured. These parameters were assessed at 30, 60, 90, and 110 degrees of flexion in ten intact stifles. Similar measurements were carried out after division of the caudal (posterior) cruciate ligament, followed by division of the meniscofemoral ligament. The sequence of division was reversed for a further ten stifles.

Division of the meniscofemoral ligament resulted in an 18–38% increase in posterior translation at all angles of flexion, both in the intact and in the caudal cruciate ligament-deficient stifle (p< 0.05). There was no significant increase in anterior translation. This effect was largest with the joint relatively extended (at 30°). Division of the meniscofemoral ligament also resulted in a 5–32% increase in internal rotation of the tibia after application of a 6Nm torque in the caudal cruciate-deficient knee. This was significant at 30° and 110° flexion (p< 0.05).

The meniscofemoral ligament is a significant secondary restraint in resisting the posterior draw and internal tibial rotation in the sheep stifle joint. This is the first study demonstrating a functional role for this structure in any animal. Its counterpart in the human is the posterior meniscofemoral ligament of Wrisberg. Several studies have demonstrated similarities between the sheep stifle and the human knee. Confirmation of a similar role for the ligament of Wrisberg in the human knee would have a significant bearing on the prognosis and management of the posterior cruciate ligament injured knee.

Nicotine is a constituent of tobacco smoke and is present in the body fluids of smokers^1,2. Numerous studies have confirmed that smoking is a strong risk factor for back pain³. The most widely accepted explanation for the association is that smoking leads to malnutrition of spinal discs due to carboxyhaemoglobin formation. However, other constituents of smoke, such as nicotine, may also be responsible for intervertebral disc (IVD) degeneration by leading to cell necrosis in both the nucleus pulposus and annulus fibrosis. Despite evidence suggesting the detrimental effect on a variety of tissues, the effect of nicotine on IVD cells has not previously been investigated. This study investigated the influence of nicotine on the metabolism and viability of IVD cells cultured in vitro.

Bovine nucleus pulposus (NP) intervertebral disc cells were isolated by sequential digestion of caudal spinal disc nuclei with pronase and collagenase and seeded in 2% alginate at 5x10⁶ cells/ml. The constructs were cultured for 21 days in standard culture medium (DMEM + 20% Fetal calf serum) containing free base nicotine (Sigma) at concentrations ranging from 25nM and 300nM, which reflected the normal physiological concentrations found in the serum of smokers. The medium was replaced every 3 days and representative constructs were removed from culture, digested and assayed for DNA, glycosaminoglycan (GAG) and hydroxyproline content at time points 3, 7, 14 and 21 days. Further constructs were processed for standard histology and immunolocalisation of collagen types I, II and chondroitin-6-sulphate.

The results were analysed statistically using an ANOVA test followed by a non-parametric Dunnit’s test. NP cells demonstrated a dose dependent response. At 25nM dose of nicotine there was a significant increase (p< 0.05) in DNA content, GAG and collagen synthesis in the constructs. At 100nM, 200nM and 300nM doses, there was a significant dose dependent decrease (p< 0.05) in all of these parameters compared to controls cultured under nicotine free conditions. In addition, adverse morphological changes were observed on histology, which included reduced cell proliferation, disrupted cell architecture, disintegration of cells and extracellular matrix. Immunohistochemistry showed the production of type I collagen rather than type II collagen as in the controls.

Nicotine has an overall detrimental effect on cultured nucleus pulposus disc cells in vitro. There was significant inhibition of cell proliferation and extracellular matrix synthesis. Nicotine in tobacco smoke may therefore play a role in the aetiology of disc degeneration that leads to back pain in smokers.

Studies comparing the biomechanical properties of different meniscal repair systems are limited, and most have simply investigated load to failure. Meniscal tissue is highly anisotropic, and far weaker under tension in the radial direction. Loading to failure using high radially orientated loads may, therefore, not be the most physiologically relevant in-vitro test for repair of circumferential tears, and determining increases in gapping across repair sites under cyclical loading at lower loads may be of greater importance. This study aimed to determine the load to failure for 4 different meniscal repair techniques, and to assess gapping across repairs under cyclical loading.

Bovine menisci were divided vertically, 5mm from the peripheral edge to simulate a circumferential tear, and then repaired using 1 of 4 techniques: vertical loop sutures using 2-0 PDS, bioabsorbable Meniscal Arrows (Atlantech), T-Fix Suture Bars (Acufex) or Meniscal Fasteners (Mitek). 9 specimens were tested in each group using an Instron 5565 materials testing machine with Merlin control software to determine load to failure. A further 9 specimens in each group were tested by cyclical loading between 5N and 10N at 20mm/min for 25 cycles. Gapping across the repairs under cyclical loading was measured using a digital micrometer and a Differential Voltage Reluctance Transducer.

The peak load to failure values for each repair method did not appear to fit a Gaussian distribution, but were skewed to the left due to some samples failing at lower loads than the main cluster. Results were analysed using the Kruskal-Wallis test, with Dunn’s multiple comparison post test. The results for gapping across the repairs from the cyclical testing all appeared to fit the Gaussian distribution, and these were analysed by Analysis of Variance, with Tukey’s multiple comparison post test. All analysis was performed using Prism (Graph-pad) Software.

The mean loads to failure for each of the repair groups were: Sutures 72.7 N, T-Fix 49.1 N, Fasteners 40.8 N, and Arrows 34.2 N. The load to failure was significantly greater with the Suture group compared to the Arrows (p< 0.01) or the Fasteners (p< 0.05). The mean gapping across the repairs for each of the repair groups after 25 loading cycles were: Sutures 3.29mm, Arrows 2.18mm,Fasteners 3.99mm,andT-Fix 3.47mm.The mean gapping was significantly less for the Arrows compared to the Sutures (p< 0.05), the Fasteners (p< 0.01), or the T-Fix (p< 0.05).

The results confirm that meniscal repair by suturing gives the highest load to failure, but show that Arrows give superior hold under lower loads, with the least gapping across repairs under cyclical loading by this testing protocol.

The role of matrix metalloproteinases (MMPs) in the aseptic loosening of hip prostheses is well established. Gelatinase MMPs have been identified in the interface membranes and the pseudosynovial tissues in the hips. Little data are available on gelatinase MMPs and their major regulators, including specific tissue inhibitors of matrix metalloproteinases (TIMPs) in the loosening of shoulder prostheses. The objectives of this study were to determine whether A) gelatinase MMPs and their regulators (MMP14, TIMP-1,-2) are produced by periprosthetic tissues in cases of aseptic loosening of shoulder prostheses, and, B) to identify which cell types, in both interface and synovial tissues, localize the enzymes.

Interface tissues and synovial tissues were obtained during revision surgery for loose shoulder implants. In 9 patients (6-Total Shoulder Replacement, 3-Hemiarthro-plasty (Bipolar), 9 samples of interface tissues and 8 samples of synovial tissues were obtained. Of the interface tissues 2 were from the interface of the bipolar and the unresurfaced glenoid. Formalin-fixed paraffin embedded sections were stained using primary antibodies for MMP2 (Neomarkers), MMP9 (Oncogene Ltd), TIMP1, TIMP2 & MMP14 (Chemicon Ltd). Antigen retrieval required pressure cooker treatment for MMP2 and MMP9 and trypsin for TIMP1. Visualisation used a standard DAB chromagen technique (Envision, Dako Ltd.). Appropriate control sections ensured reproducibility of the staining. The antibodies selected bind to both active and inactive forms of the MMPs.

Both HDPE and metal debris were seen in both the synovial and interface tissues. Transformation of macrophages to giant cells was associated with PE debris, and was not observed with metal debris alone.

The presence of gelatinase MMPs in both interface and synovial tissues in aseptic loosening of shoulder prostheses was demonstrated. Differences between the MMP content of macrophages and giant cells between the tissues was detected, positivity was associated with the presence of metallic and/or HDPE debris. Activation of endothelial MMP2 by both MMP14 and low levels of TIMP2 would support the development of a vascular network.

During the last few years there has been renewed interest in hip resurfacing. The advantages of such prostheses include minimal bone resection and more physiological loading of the proximal femur. The purpose of this study was to investigate the stress distribution to the upper femur following a metal-on-metal hip resurfacing and the influence of a short stem on femoral bone loading.

An accurate and validated finite element (FE) model of the proximal femur was utilised. This was created from CT data of cadaveric femurs. The validation process included weighing, modal analysis, strain gauging and ultrasound material testing of the bone. The maximum elastic modulus in the principal direction was 22.9ÊGPa. The elastic moduli of the cement and implant were 1.8 and 200 GPa respectively. The joint force and 4 muscle loads were applied accordingly and adapted to the specific geometry of the bone. The load case represented the 45% position in the gait cycle, corresponding to toe-off. The hip joint force of 2.2kN, approximately 30° superior to the pole of the implant, was applied as a pressure distribution over a 60° spherical segment, modelling the large contact area of the metal-on-metal articulation. Various scenarios with and without an implant were compared.

The distribution of the von Mises stresses in the normal femur without an implant reflected the distribution of the bone’s mechanical properties: the joint load was transferred from the superior surface of the femoral head, through its centre to the dense cortical bone of the calcar and diaphysis. The presence of the resurfacing prosthesis did not significantly affect the stress distribution in the proximal femur, except for a reduction of stresses in the superior region of the femoral head. Varying the length of the stem and its fixation did not significantly affect this stress distribution. A resurfacing prosthesis without a stem resulted in more normal stresses in the superior region of the femoral head.

Compared to the normal femur without an implant the FE analysis of the resurfacing prosthesis demonstrated stress shielding in the superior region of the femoral head. This stress shielding was reduced when a resurfacing component without a stem was used. This advantage must be weighed against the disadvantage that without a stem it is more difficult to accurately position the implant and achieve a uniform cement mantle.

Dual Energy X-ray absorption (DEXA) has been used to measure bone mineral density (BMD) around total hip prostheses. With the recent increase in the use of metal on metal hip resurfacing, such as the Birmingham Hip Resurfacing (BHR), there has been renewed concern over per prosthetic femoral neck fracture and implant loosening. DEXA quantitatively measures bone mineral density and therefore could predict impending loosening and fracture. To the best of our knowledge, there are no recorded studies assessing BMD around metal-on-metal hip resurfacings such as the BHR. Our intention was to produce a reliable method of measuring bone density around a metal-on-metal hip resurfacing, such as the BHR, prior to a prospective study.

We performed DEXA scans on five patients (7 BHR’s), who had undergone resurfacing with the BHR within the last two years, using the Hologic QDR 45000A scanner. Each BHR was scanned twice on the same day with complete patient repositioning between scans. We analysed the data with the Hologic prosthetic hip (v 8.26a: 3) scan analysis software (operating software 9.80D) by identifying a variable number of same-sized regions of interest (ROI) within the femoral neck. These ROI’s were derived from an inter-trochanteric line and the axis of the BHR stem in the femoral neck. Each of the 14 scans was analysed twice, by three of the authors independently; with at least one week between repeat analysis by the same observer. Statistical analysis was carried out by the local University Department of Statistics.

The variation within the same ROI in a given BHR was 0.00353, whereas the variation between all ROI’s was 1.155. The intraclass-correlation was 0.997 (i.e. the correlation between any two assessments of one ROI) with an overall coefficient of variation of 5%. The variation between the two scans for each BHR and between the three assessors was not significant (p=0.87 and p=0.42 respectively). The mean BMD of the individual ROI’s, between the two assessments of the same scans by the same assessor (i.e. intra-observer variation) was lower on the second assessment by 0.0214gcm⁻² (SD=0.0025) representing 0.5% mean density for all ROI’s. This difference was statistically significant (p< 0.001).

This method demonstrates excellent reproducibility of the method. Inter-scan and inter-observer variation was so negligible that a tiny intra-observer variation of 0.5% (of mean bone density) became statistically significant (p< 0.001), despite it making no difference to the overall intraclass-correlation. Statistical advice suggested that this very small difference in mean density (intra-observer) only reached significance due to the highly sensitive measurements and excellent reproducibility.

We have designed and demonstrated a safe, non-invasive and highly reproducible method for scanning BHR implants in vivo using DEXA. We will now use this method to prospectively study our BHR population to detect impending loosening or fracture.

Patient disability and handicap following wrist injuries have been the focus of recent research interest¹. However, the relative importance of each of the commonly-reported and easily-measured clinical outcome parameters such as the range of wrist movement and the grip strength on the level of actual wrist disability following distal radial fractures has not been investigated previously. The present study investigates the correlation between measurements of specific clinical parameters and the patient-rated wrist joint function following wrist fractures.

A prospective assessment of unstable (AO types 23-A2, -A3, -C1 and -C2) fractures of the distal radius treated by closed reduction and percutaneous K-wire fixation followed by cast immobilisation was undertaken. One hundred consecutive observations were made during various follow-up time periods up to one year in a group of twenty-five patients (fifteen female and ten male patients, mean age 43 years – range 18 to 67 years). The clinical parameters tested were the range of wrist dorsiflexion, palmarflexion, pronation and supination (measured using a goniometer) and the mass grip strength (Jamar grip dynamometer) following removal of the plaster cast, expressed as percentage of the affected side relative to the opposite normal side. Additionally, each patient completed the Patient-Rated Wrist Evaluation (PRWE) Score¹. A stepwise multiple regression multivariate model was employed to statistically analyse the relative effect (expressed as the regression coefficient, b) of each clinical parameter on the ‘Function Score’ part of the PRWE Score. Furthermore, the association between each clinical parameter and the Function Score part of the PRWE Score was also investigated using single-patient observations by calculating the correlation coefficient (r).

The results of the statistical analysis (Minitab 12.1) gave the following regression (b) and correlation (r) coefficient values: grip strength (b=0.77, r=0.80), dorsiflexion (b=0.58,r=0.78),pronation (b=0.39,r=0.70),supination (b=0.38, r=0.63), palmarflexion (b=0.32, r=0.62).

The present study shows that grip strength (expressed as percentage that of the unaffected side) is the most reliable index of wrist disability and the most sensitive indicator of return of wrist function, followed by the range of wrist dorsiflexion and pronation. Wrist supination and palmarflexion are the clinical outcome variables showing the weakest correlation with the wrist function as rated by the patients. These observations may facilitate correct interpretation and comparisons of the results of clinical studies on various methods of treatment of wrist trauma.

Aseptic loosening is generally associated with the presence of wear particle-associated macrophages in the pseudomembrane commonly formed around failed prosthetic implants. The extent of the macrophage response evoked by the wear particles has been shown to correlate with the amount of periprosthetic osteolysis. Numerous studies have shown that wear particle-associated macrophages contribute to osteolysis by (i) releasing inflammatory cytokines and/or (ii) differentiating into bone resorbing osteoclasts. Although macrophages and macrophage polykaryons are the main inflammatory cells found in periprosthetic tissues, numerous fibroblasts are also present in the connective tissue pseudomembrane. The recently identified molecule, RANKL has been shown to play a central role in the osteoclast formation and bone resorption observed in aseptic loosening. We have shown that arthroplasty macrophages, which express RANK, the receptor for RANKL, are capable of osteoclast differentiation; this process is inhibited by osteoprotegerin (OPG), the soluble decoy receptor for RANKL. As fibroblasts are known to express RANKL, the aim of the present study was to determine whether fibroblasts isolated from periprosthetic tissues could induce the generation of bone resorbing osteoclasts that would contribute to the osteolysis commonly seen in the periprosthetic loosening.

Fibroblast-like cells were isolated from pseudomembrane from patients (n=5) undergoing hip revision due to aseptic loosening, by routine collagenase enzyme digestion. The isolated cells were seeded in flasks for 2–4 weeks before being passaged for a further 3–4 times. Generated fibroblast-like cells (10⁴) were then co-cultured with 5x10⁵ normal human peripheral blood monocytes (n=5) on glass coverslips and dentine slices in the presence of (i) no added factors, (ii) macrophage colony stimulating factor (M-CSF) and (iii) M-CSF plus OPG. All cultures were maintained for 1,17 and 21 days. The extent of osteoclast differentiation was then determined by the expression of specific osteoclast markers including tartrate-resistant acid phosphatase (TRAP) and vitronectin receptor (VNR) and evidence of lacunar resorption.

In the absence M-CSF, no osteoclast formation was noted in 24 hours, 17 or 21 days in fibroblast/monocyte cultures. However, in the presence of M-CSF alone, large numbers of TRAP⁺ and VNR⁺ multinucleated cells capable of lacunar resorption were noted in these co-cultures. The addition of OPG, which is known to inhibit RANKL-mediated osteoclast formation, significantly reduced the extent of osteoclast formation and lacunar resorption in these co-cultures.

These results indicate that one means whereby peri-prosthetic osteolysis may occur is by fibroblasts in the arthroplasty pseudomembrane inducing macrophage-osteoclast differentiation. Fibroblasts express RANKL and interact with arthroplasty macrophages, which express RANK and function as osteoclast precursors. These findings indicate that suppression of osteoclast formation by OPG may be a possible form of therapy for reducing prosthetic loosening.

Aseptic loosening of total joint arthroplasty is characterised by osteolysis that is caused by osteoclasts and macrophages. The mechanism of bone resorption is by acidification, dissolution of hydroxyapatite crystals then proteolysis of the bone collagen matrix. The collagen cross-link molecules are cleaved by osteoclasts exposing the N terminal of the cross-link protein - N Telo-peptides (NTx). This represents a highly specific marker for bone resorption. Previously described bone resorption models include radiolabelled animal bones which require the use of animals and radioactive materials or thin dentine slice resorption pits which are only semi-quantitative and technically difficult to produce. NTx could be a potential osteolysis marker in the laboratory investigation of aseptic loosening with the advantage of being cheaper and easier to perform compared to present established marker and also does not require animals or radioactive materials. The aim of this study was to show that NTx generated during osteolysis by cells extracted from human interface membranes of aseptically loosened hips correlates with the established radiolabelled ⁴⁵Ca bone resorption model.

Cells from human interface membranes of aseptic loosened hip joints were extracted from the tissue following enzyme digestion. These cells were cultured with dead radiolabelled (⁴⁵Ca) mice calvaria discs in the presence of 1,25 dihydroxyvitamin D₃, hydrocortisone, RANKL and M-CSF. In the control culture no cells were added to the culture system. Calvaria discs used for each experiment comparison were from the same parietal bone. The supernatant culture medium were extracted on day 3, 7, 10 and 14 and assayed for NTx and by scintillation counting. On day 14 the remaining culture medium and cells were assayed by scintillation counting. The remaining bone samples were decalcified and the total remaining ⁴⁵Ca in the bone was measured.

All results were expressed as the ratio of bone exposed to cells (BC)/bone only (B). Supernatant samples for ⁴⁵Ca showed a rise in BC/B ratio with time 0.83, 0.88, 0.97 and 1.08 (p= 0.0001). Supernatant samples for NTx also showed a rise with time 1.06, 1.21, 1.41 and 1.40 (p=0.03). In the bottom sampling for ⁴⁵Ca the mean ratio of BC/B was1.8 (p=0.0001) and the BC/B ratio for the remaining radioactivity in the bone at the end of the culture was 0.81(p=0.0007). There was a strong correlation between ⁴⁵Ca and NTx (r= 0.9).

The absolute values of ⁴⁵ Ca dropped initially due to the uptake of calcium by the cells and this explains our previously unsuccessful attempt to use non radioactive calcium as a marker of bone destruction. We believe this is the first time human interface membrane cells have been shown to release NTx during osteolysis in an in vitro model. Replacing ⁴⁵Ca radiolabelled bone with NTx as a marker represents an important step towards simplifying and reducing the cost of an in vitro model of particle induced osteolysis

Mast cells (MC), the tissue-based effector cells in allergic diseases, have many functions. Within bone tissue, they have been linked with new blood vessel formation and marrow fibrosis and it has been proposed that they are capable of promoting osteoclastic bone resorption. MC numbers are known to increase in a number of osteolytic conditions e.g. osteoporosis, hyperparathyroidism and periodontitis. In fracture callus, too, large numbers of MC are present, especially during the onset of remodelling where it is believed they may be responsible for osteoclast recruitment and/or differentiation. The aim of this study was to look for further evidence of mast cell (MC) involvement in pathological bone resorption. MC activity was assessed in tissue sections of osteolytic conditions including Paget’s disease of bone, rheumatoid arthritis and fibrous dysplasia together with several benign and malignant bone tumours. MCs were identified by toluidine blue staining and by immunostaining with a commercial antibody against MC tryptase.

Extensive infiltration of mast cells was observed in fibrous dysplasia, rheumatoid arthritis and Paget’s disease of bone and mast cell accumulation was seen at the bone resorbing margin of a number of enlarging bone tumours including osteosarcoma, giant cell tumour of bone, osteoma and osteoid osteoma.

MCs, along with other inflammatory cells, are known to accumulate at the margins of soft tissue tumours where they are thought to promote tumour growth. The current findings are consistent with a similar role for mast cells in the primary bone tumours examined. In each of the conditions studied, an additional role for MC may be that of promoting bone lysis. MC are known to contain numerous factors including TNF-alpha and IL-1, which are potent stimulators of osteoclast formation and activity.

It is concluded that MCs may contribute to the fibrosis, angiogenesis and increased bone resorption seen in certain metabolic bone diseases. MC activity may also be an important factor contributing to the lysis that occurs in numerous other pathological situations including at the margins of aggressive primary bone tumours and skeletal metastases, leading to the expansion of these lesions.

This study examined the effect of surgical approach on the 1year migration of the Exeter stem, using Roentgen Stereophotogrammetric Analysis (RSA). There is evidence that implants with increased early migration, particularly those moving into internal rotation, are likely to have a higher failure rate.

A total of 46 patients awaiting THR were allocated into 2 groups. Both groups underwent an Exeter Total Hip replacement, one through the Posterior Approach (PA), and the other through the Hardinge Approach (HA). RSA was used to assess post-operative stem position and migration at 1 year. Post-operative gait analysis and clinical evaluation was used to assess a subgroup of patients.

There was no difference in the initial stem position of each group within the femoral canal. Significant differences in migration were found for migration of the head distally and posteriorly and for the tip medially. During gait, the legs of the PA group were relatively internally rotated when compared to those of the HA group. Relative to the supporting bone, the PA implants internally rotate and also rotate into valgus further than the HA implants. The starting position of the prostheses was the same and the cement and prosthesis characteristics were similar. From this, we can infer that surgical approach and therefore muscle function, have a large influence on component migration. During gait, the PA group had internally rotated legs compared to the HA group. This is probably due to short external rotator weakness in the PA group. As a result the internally rotating component of the posteriorly directed joint reaction force on the femoral stem will be larger. This probably explains the rapid internal rotation seen in the implants of the PA group. With the HA group, because of abductor damage there is likely to be a smaller component of the joint reaction force acting on the stem. This would explain the smaller rates of observed coronal plain rotation (rotation into valgus).

Profound differences exist in early migration, between the HA and PA. Different muscle function may account for this and probably influences long-term outcome.

The objective of this study was to examine patients’ use of the Internet to obtain medical information, their opinions on the quality of medical Web sites and their attitudes towards Internet-based consultations.

The study made use of a questionnaire given to 398 patients, aged 10 to 95 years (mean 55 years), visiting the orthopaedic outpatient clinics of a London district general hospital over a 2 week period. The major outcome measures were; 1) the rate of Internet use by patients, 2) the perception of the quality of medical websites, 3) future intentions and attitudes towards internet-based consultations, and 4) concurrence between information obtained from Web sites and advice given by the orthopaedic surgeon in the clinic. Results were considered significant at p< 0.05. The Chi² test was used to compare proportions. Spearman’s correlation coefficients were used to quantify correlation.

From 369 respondents (response rate 91%), 55.3% of patients had accessed the Internet. Of these 52.0% had obtained medical information from this source. Access was linearly correlated with age (r² =0.975, p< 0.01) and was also related to social status. Of the 12.3% of patients who had researched their particular orthopaedic condition, 20% reported that the advice received from the surgeon in the clinical contradicted that obtained from the Internet. A total of 37.5% of patients would undergo an Internet-based consultation, whilst a further 25.5% would consider this, depending on the medical condition in question.

This is the first detailed UK study examining patient attitude towards Web-based medical learning. Over half of the patients were willing to access the Internet for medical information, with younger patients more likely to undertake this activity. As the commercial advantages of a captive patient population become apparent, there is the potential for inaccurate or misleading information, that has not undergone peer review, to be disseminated over the Internet The increased use of medical Websites by patients raised important issues regarding the need for quality control, which orthopaedic surgeons and their institutions both need to address. This also impacts significantly upon the changing nature of the surgeon-patient relationship.

Dupuytren’s contracture is characterised by abnormal fibroblast proliferation and extracellular matrix deposition in the palmar fascia. Fibroblast proliferation and matrix deposition in connective tissues are regulated by cytokines. A number of cytokines including transforming growth factor beta (TGFβ), basic fibroblast growth factor (bFGF), platelet derived growth factor (PDGF) and epidermal growth factor (EGF) are known to have potent anabolic effects on connective tissue. The aim of this study was to investigate the role played by anabolic cytokines in the pathogenesis of Dupuytren’s disease.

Twelve specimens of Dupuytren’s contracture and six control specimens of palmar fascia obtained from patients undergoing carpal tunnel release were cultured using a serumless method under standard conditions for 72 h. Levels of TGFβ-1, bFGF, PDGF and EGF in the medium were estimated using an enzyme linked immunoabsorbent assay technique.

Neither Dupuytren’s tissue nor control palmar fascia produced any EGF. The mean (±S.D.)levels of bFGF, PDGF and TGFβ-1 produced by cultured palmar fascia were: 1270 ± 832, 74 ± 24, < 7, and for Dupuytren’s tissue were 722 ± 237, 139 ± 76.6, 645 ± 332, respectively. The levels of PDGF and TGFβ-1 were significantly higher in Dupuytren’s tissue.

PDGF is produced in increased amounts by Dupuytren’s tissue. This may contribute to the fibroblast proliferation and increased ECM deposition observed in this condition. TGFβ-1 is not produced by normal palmar fascia but is produced in large amounts by Dupuytren’s tissue. The major physiologic role of TGFβ-1 is to stimulate formation of fibrous tissue. It plays a major role in wound healing and also in pathological conditions where fibrosis is a prominent feature. Inappropriate production of TGFβ-1 in the palmar fascia in Dupuytren’s disease may play a central role in initiating and stimulating the abnormal fibroblast proliferation and collagen synthesis seen in this condition.

The detection and treatment of acute compartment syndrome following trauma is critical if contractures, delayed fracture healing and possible amputations are to be avoided. The current standard for monitoring relies on invasive compartment pressure measurements. These require an additional procedure and cause discomfort to the patient. This prospective clinical study investigates the relationship between the intra-compartmental pressure and soft tissue oxygenation (%StO₂) measured non-invasively by near-infrared spectroscopy (NIRS) in patients at risk of acute compartment syndrome.

Adults with acute tibial or radial diaphyseal fractures were recruited on admission to the orthopaedic trauma unit. Non-invasive and invasive monitoring over anterior tibial or volar forearm compartments was carried out from admission and continued post-operatively. The differential pressure (ΔDP) was calculated as the compartment pressure subtracted from the diastolic blood pressure. The threshold for fasciotomy was a ΔDP < 30mmHg. StO₂ values were simultaneously recorded from the contralateral (uninjured) limb at the same site. All patients had the difference between the StO₂ value on the injured and uninjured sides calculated (‘StO₂ difference’).

Sixty patients with tibial fractures and 5 patients with forearm fractures were recruited. The mean age was 39 years (S.D.18 years). Fourteen patients underwent a four-compartment lower leg fasciotomy determined by a ΔDP < 30mmHg.

We have observed that the difference in StO₂ between limbs (measured non-invasively) was significantly lower in patients undergoing a fasciotomy. This suggests that NIRS is able to detect a change in oxygenation of the soft tissues in trauma patients developing an acute compartment syndrome. We are optimistic that near-infrared spectroscopy (NIRS) will be a reliable new non-invasive technique for detection of an acute compartment syndrome.

This study aimed to A) establish a protocol for measuring periprosthetic bone mineral density (BMD) of the proximal humerus following implant arthroplasty, and B) compare the differences in the periprosthetic BMD values 4–9 years after surface replacement and stemmed arthroplasties of the proximal humerus. The study design was of retrospective independent samples cohorts, of patients who had received a proximal humeral arthroplasty between January 1992 and December 1996 in a tertiary referral shoulder unit of a UK hospital. The exclusion criteria were A) patient unavailable for study, B) patient refusal, C) inadequate information of dependent and independent variables, or D) obvious measurement errors.

All available patients underwent DEXA scanning of the proximal humerus using a Lunar DPXL scanner fitted with Orthopaedic Hip software version 1.3. Replicable patient positioning with a special jig was used. On a predetermined format of Gruen equivalent zones and sub-zones, BMD values in gm/cm² were plotted. Cortical thickness on plain radiographs was recorded for each zone. Femoral neck DEXA scan was performed to obtain a proportionate value of BMD of the proximal humerus, in order to eliminate the effect of confounding variables. Confounding variables accounted for were age, gender, height, weight, activity level, indication for surgery, duration of implantation, dominance, type of arthroplasty (hemi or total) and use of cemented or uncemented stemmed implants. Statistical analysis was performed using Microsoft excel as well as SPSS software.

Initially, 58 shoulders in 52 patients were recruited. 6 patients declined to participate for ill health, 6 had moved out of the area and 8 did not attend or reply. Of the remaining 31 shoulders in 25 patients, 2 patients had an obviously erroneous DEXA reading. 29 shoulders in 23 patients were finally analysed, which included 10 male and 19 female shoulders. Average age was 67.5 years and average time since surgery was 6 years 2 months. Indications for surgery were RA in 14, OA in 8 and other reasons in 7. Of 29 shoulders, 20 received a total replacement, 9 a hemiarthroplasty.

The inevitable obliquity of the image caused some difficulties in maintaining accuracy and difficulties were observed due to limitation of the software to measure thin cortices and to distinguish between the cement and bone. There was no significant correlation between gross cortical thickness and BMD values, and the average periprosthetic BMD was 0.54 g/cm². Surface replacement implants were associated with relative preservation of proximal medial cortex and higher BMD values in this region. BMD values were consistently higher at the level of stem tip for the stemmed implants. No such phenomenon was observed for the surface replacement prostheses. Hemiarthroplasty was associated with relatively higher BMD values in the proximal medial cortical region than total arthroplasty.

A high incidence of complications with wound healing in calcaneum fractures treated with open reduction and internal fixation (25 – 33% of cases) has been reported. In one study 80% of those who had wound complications required surgical treatment of these. Two recent studies have shown that the risk factors for wound complications in this injury are single layered closure, high BMI, extended time between injury and surgery, diabetes, open fractures and smoking. In our unit, out of a small sample of 56 patients undergoing calcaneal fracture fixation, all those who developed wound complications were smokers.

Transcutaneous oximetry is a technique that has been used routinely to assess oxygen perfusion in neonates and also sometimes in peripheral vascular disease (PVD). It has seen greater use as a research tool in PVD and orthopaedic surgery, being used to look at oxygenation around wounds to assess different surgical approaches. This study was performed to assess whether a difference in the oxygen perfusion around the ankle joint could be measured in smokers and non-smokers. A transcutaneous oximetry probe was used to assess the tissue oxygen perfusion at the ankle (posterior to lateral malleolus where the incision line would be) and on the chest (just to the side of the sternum). A standardised technique was used for each patient.

Patients were chosen who had no lower limb orthopaedic problem or known PVD. The groups were matched in terms of sex and average age. The data was analysed after logarithmic transformation using a two-tailed Students t-test. The average pO2 chest/foot ratio was higher in the non-smokers than smokers but this was not significant (p=0.704). The average ankle pO2 was higher in the non-smokers and this was shown to be significant (p=0.026).

Although a small sample, these data suggest that tissue oxygenation around the ankle may be significantly lower in smokers. This would help to explain why they are at increased risk of wound healing complications. This work also demonstrates that transcutaneous oximetry can be a useful tool in orthopaedic research. Tissue oxygenation around other joints could also be assessed in relation to position to discover the optimum position for wound healing.

Disuse osteoporosis of the greater tuberosity is a consequence of rotator cuff tear. This is a significant problem as the tendon is implanted into a trough within the greater tuberosity during repair. Failure of the repair is a common complication (up to 50%). We hypothesized that failure in re-implantation is due to deficient bone cell response to mechanical stimulation in the tuberosity. In order to establish whether these cells are capable of responding appropriately to mechanical stimuli, the response of bone cells derived from the tuberosity was compared with that of cells derived from the acromion. This was measured in terms of strain related increases in alkaline phosphatase (ALP) activity, nitric oxide (NO) and prostaglandin (PG) production (which are recognised markers of osteoblast differentiation and their response to mechanical strain).

Primary osteoblasts were cultured from samples of acromion and greater tuberosity taken during routine rotator cuff repair (n=5 pairs). The derived cells were placed under cyclic strain at a physiological magnitude for 10 min at 1Hz using well established controls. Samples of media were analysed for changes in NO and PG production and the cells were reacted for ALP. Cells were stimulated with dexamethasone, ascorbic acid and beta-glycerophosphate (established mediators of osteoblast differentiation) then reacted for ALP.

Preliminary results suggest that cells derived from the acromion exhibit significant increases in cellular NO release and in ALP activity, whereas cells derived from the humeral greater tuberosity fail to exhibit any such increases. In marked contrast cells derived from both sites exhibit increases in ALP activity in response to dexamethasone, ascorbic acid and beta-glycerophosphate treatment.

The results suggest that whilst cells derived from the tuberosity after rotator cuff tear respond appropriately to chemical and hormonal stimuli, they are compromised in their ability to respond to mechanical stimulation. It is tempting to speculate that such relationships are also evident in vivo and that they underpin reimplantation failures.

The growth plates of rapidly growing animals have been studied extensively. Nevertheless, several questions remain unanswered, partly because many events happen simultaneously, especially at the vascular front. Terminal chondrocytes are thought to undergo programmed cell death, but the fate of the cell remnants remains unclear. Are the dying cells released into the vascular space and phagocytosed by macrophages, as one would expect for apoptosis? Or are the cells eliminated prior to opening of the lacunae, leaving empty lacunae? Do all terminal chondrocytes die or do some become bone-forming cells? Rodents maintain a growth plate into old age, long after longitudinal growth has ceased. These stationary growth plates have several features not found in the growth plates of rapidly growing animals and closer study of these features may provide answers to the above questions. Femurs and tibiae from 4–16 week-old and 62–80 week-old rats were decalcified, processed into paraffin, and the morphological changes were documented.

Between 4–16 weeks, the heights of the growth plates decreased due to loss of the large hypertrophic chondrocytes, but the various zones were still present. In the aged rats, the growth plates were identifiable as a narrow cartilaginous band with some short columns of inactive cells. The vascular front was irregular, the narrow spicules of primary spongiosa were absent and the much thicker spicules, which are normally seen in secondary spongiosa, directly abutted to the cartilage. Horizontal apposition of bone matrix onto the cartilage edge was frequently present. In addition, the following features were noted. 1) Acellular areas: Nearly all growth plates contained regions of cartilage from which all cells and their lacunae had disappeared. In some cases, these acellular regions stretched from the reserve zone to the vascular front and even persisted as a relatively wide core within the spicules of spongiosa, indicating increased resistance of acellular cartilage to resorption. The absence of cells or cell debris was consistent with an autophagic mode of cell death and subsequent collapse of the lacunae. 2) Remodelling within the growth plate; in some growth plates, large regions of growth plate cartilage had been resorbed and new bone had been laid down in a pattern similar to the remodelling of cortical bone. This suggested that the normal resistance of cartilage to vascular invasion had been lost locally, but was maintained in adjacent non-remodelled regions. 3) Trans-differentiation of chondrocytes to bone-forming cells; extensive new medullary bone formation was noted in the diaphysis of approximately 30% of the aged rats, suggesting that they had received an (unknown) osteogenic stimulus. In these rats, bone matrix was identifiable inside chondrocytic lacunae, and spreading beyond the confines of the lacunae, thus directly replacing growth plate cartilage with bone matrix.

The results suggest that i) chondrocytes are capable of self-elimination, perhaps by a mechanism similar to the autophagic cell death that occurs during insect metamorphosis; ii) resorption of cartilage and vascular invasion requires the presence of the viable chondrocytes; and iii) chondrocytes have the capacity to transdifferentiate to bone-forming cells, but only do so when receiving an increased osteogenic stimulus.

Osteoporosis has been implicated as one of the causative factors for Colles’ fracture. The current study was designed to establish whether the degree of osteoporosis has any influence on the radiological severity of Colles’ fracture in active elderly peri-menopausal female patients.

Female peri-menopausal patients who sustained a Colles’ fracture were studied. The ultra distal Bone Mineral Density (uBMD) was determined using DXA in the contralateral non-fractured wrists, which were also x-rayed. Anthropometric measurements were recorded, the radiological severity of the fracture was assessed using a computerised image analysis system, which measured the radial angle, height and width on AP view and the dorsal tilt on lateral view. Measurements were carried out on the fractured and the normal wrist. Pearson’s correlations between age, height, weight, BMI, uBMD and fracture measurements were carried out. The Bone Deformity Index (BDI) was defined as the summation of all the differences of the previous parameters between the normal and fractured wrists on the AP view. ANOVA, with bonferroni correction, was used to compare the parameters and the radiological measurements between normal, osteopenic and osteoporotic patients.

Sixty-seven patients were recruited. Those with Barton fractures, previous fractures of the wrist or a previous history of chronic treatment with bone modifying drugs were excluded. Forty eight patients were analysed. The parameters measured had a tendency to be worse with increasing degree of osteoporosis, although the only significance was in the measurement of dorsal tilt on the lateral view (p = 0.05). The normal patients were significantly heavier (89.3 kg) than the other two groups (p =0.03). In the osteoporotic group the correlation between uBMD and the BDI was −0.6, between uBMD and radial height difference was –0.5 and between uBMD and the angle difference in AP was also –0.5. Similar correlations in normal patients were not statistically significant. Power estimates were performed. Because of the relatively large variability within the samples, a sample size of 550 cases will be necessary to reach a power of 80% to detect a pre-defined clinically significant difference of 3 units in the BDI between groups.

The evidence from this study suggests that the initial radiological deformity in osteoporotic patients was greater in those patients with severe degree of osteoporosis. The deformity in normal patients did not have a correlation with the uBMD but these patients were significantly heavier, indicating a different combination of causative factors in these two groups. The precision of the current method of x-ray measurements has enabled a precise definition of the variability within the different groups, resulting in the production of information that was not previously available.

Enzymes that breakdown components of the extracellular matrix (ECM) are of fundamental importance, not only in normal bone physiology but also in pathological processes. For instance the temporal and spatial distribution of proteoglycans is not only critical for the mineralisation of bone but is also believed to be responsible for dictating the local bioavailability of glycosaminoglycan-binding growth factors. A sub-family of the ADAMs (a disintegrin and metalloproteinase) has been identified, that contains thrombospondin-like motifs (ADAMTS), and ADAMTS1, 4 and 5 have recently been shown to cleave the major proteoglycan of cartilage, aggrecan. We propose that ADAMTS family members play a novel role in regulating osteoblast function by determining the distribution of proteoglycan in bone.

RT-PCR and Northern blotting experiments have shown expression of ADAMTS1, 3, 4 and 5 in primary rat osteoblasts and in the osteosarcoma cell lines, MG63, TE85 and SaOS-2. ADAMTS1 transcript levels increased with time in primary rat osteoblasts driven by dexamethasone, beta-glycerophosphate and ascorbic acid phosphate to produce bone-like nodules in vitro. Whereas levels of ADAMTS4 that were initially raised in this culture system then became undetectable as mineralisation proceeded.

Since we are interested in the relationship between the osteoblast and matrix molecules, we plated TE85 cells onto an ECM synthesised by MG63 cells and isolated RNA at 1, 24 and 48 hours. Northern analysis showed a transient upregulation of mRNA for both ADAMTS1 and 5 at 1h that was reduced to control levels at 24 and 48h. Transcripts for ADAMTS1 and 3 were also upregulated in primary rat osteoblasts when seeded on ECM molecules like fibronectin and type I collagen for 48 hours. There was however no change in the expression levels of ADAMTS4 when plated on to any of the substrates at any of the time points tested.

These data suggests that cells of the osteoblast lineage express ADAMTS1, 3, 4 and 5 and that individual transcript levels can be regulated by ECM components. The focalised production of ADAMTS family members in response to matrix-derived and other cues may be an important part of bone formation and may have important implications for the way that cells of the osteoblast lineage interact with implant and other biomaterials.

The overall incidence of cuff tears increases with age, individuals over 80years having a 51% incidence of a tear. Currently, the aetiology of rotator cuff tears remains unclear and successful repair is achieved in only 30% patients. Matrix metalloproteinases (MMPs) have roles in a wide range of physiological processes including placentation and embryogenesis, tissue remodelling and wound healing. However, the ability of MMPs to dissolve extracellular matrix has been linked to a variety of pathological processes including rheumatoid arthritis, osteoarthritis, periodontitis and multiple sclerosis, which involve excessive matrix destruction. Production of gelatinase MMPs by torn rotator cuff has been demonstrated. The objectives of this study were to examine the expression of MMPs and their association with histological changes in full thickness tears of the rotator cuff.

Rotator cuff tissue was obtained from ten patients (age 40–80years) undergoing surgical repair. The size of tear was 1–4.5cm; time from presentation to surgery was 1 month (acute) to between 0.5–4years (chronic). Immunohistochemical staining with commercial monoclonal antibodies to a range of MMPs, endothelial, macrophage and fibroblast markers was performed. Production of gelatinase MMPs was measured by gelatin zymography on tissue culture supernatant. Visualisation used a standard DAB chromagen technique.

In the acute specimens there was an infiltrate of macrophages with little collagen degeneration; the fibro-blasts were MMP1 positive and endothelial cells MMP2 positive. At 12 months post-tear mature collagen, plump fibroblasts and proliferating endothelial cells were identified adjacent to the resection edge. Towards the torn edge areas of lower cellularity, sparse vascularity and collagen degeneration were observed. Vimentin positive, CD68 negative cells within this matrix were rounded with foamy cytoplasm, and intensely positive for MMP1 and MMP2, and positive for MMP-3, -10, -11, -13 and -14. Tissue culture supernatant demonstrated active and latent MMP2 production in all cases.

The prolonged interval between trauma and surgical repair, with potential pharmacological intervention, remedial physiotherapy and disuse immobility, make assessment of the factors contributing to tendon degeneration difficult to determine. Fatty infiltration, dystrophic calcification and patchy collagen degeneration were common. However, clear evidence of cellular activities typical of wound repair were also identified, including fibroblast and endothelial cell proliferation. The most striking finding was the association between areas of poor collagen structure with fibroblasts staining intensely for both MMP1 and MMP2 and positive for other matrix metalloproteinases. The production of MMP1 and MMP2 may contribute to active remodelling of the tendon matrix. Success of repair could be influenced by both the quality of the matrix and the cell types and activities in the tissue at the resection edge.

Clinical use of glucocorticoids engenders deleterious changes in bone fragility and initiates apoptosis in osteoblasts and osteocytes. The pathways leading to corticosteroid-induced death in bone remain unclear. Similarly little is known about the effects of ‘bone sparing’ bisphosphonates on osteocytes in vivo. We investigated the effects of bisphosphonates (BPs) on dexamethasone (Dex)-induced apoptosis in the murine osteocyte cell line, MLO-Y4 and studied the putative pathways involved by intervention with inhibitors of signalling molecules, such as p42/44 MAPK and protein kinase A (PKA). Cells were preincubated with N- & non N-containing BPs and/or inhibitors before insult with Dex or H₂O₂ for 5 hrs. Apoptotic morphology was revealed by acridine orange staining. Activation of p42/44 was identified using Western blotting and in situ immunocytochemistry in the presence or absence of serum.

Both N- & non N-containing BPs were shown to protect against cell death. The addition of inhibitors of p42/44 and PKA blocked the action of Dex. H₂O₂-induced apoptosis was not blocked by BPs or by any of the inhibitors. Dex appeared to activate p42/44 only in serum supplemented cultures. These data suggest that glucocorticoid but not oxidant-induced osteocyte apoptosis involves activation of p42/44 and that bisphosphonate engendered cell rescue is brought about by inhibition of these MAPK’s. Studies using truncated BPs that lack anti-resorptive activity, and therefore do not interrupt bone remodelling showed that these BPs were also able to protect osteocytes from glucocorticoid-induced death. The ability of bisphosphonates to influence MAPK activation and cell death in the osteocyte opens up exciting possibilities for pharmaceutical intervention during age and steroid hormone related osteocyte loss.

Mesenchymal stem cells (MSCs) are pluripotential cells present in marrow, which have the ability to differentiate into osteoblasts, chrondrocytes and adipocytes. Potential skeletal tissue engineering uses include healing bone defects, spinal fusion and revision arthoplasty surgery. A means of storing viable mesenchymal stem cells is necessary in order for these cells to be readily available for clinical use. The aim of this study was to determine whether cryopreservation has any effect on the osteogenic potential of human bone marrow derived MSCs.

Five normal iliac crest bone marrow aspirates were obtained following informed consent from patients. Each aspirate was divided into two equal samples. Ficoll-separation was used to isolate the MSCs. The fresh MSCs from one sample were cryopreserved, while the other was cultured as a control population. To assess the osteogenic potential of the MSCs after cryopreservation a sample of cells from each population was cultured with osteogenic supplements and the increase in alkaline phosphatase (ALP) and osteocalcin production was compared.

Cryopreservation was not observed to effect the primary cultures of MSCs, which became confluent after a similar period in culture (12–14 days), forming colonies with recognized MSCs morphology. The expression of ALP and osteocalcin after stimulating the MSCs to differentiate with osteogenic supplements, was not significantly altered by the cryopreservation process (P> 0.05).

In conclusion MSCs obtained from fresh human bone marrow aspirates can be cryopreserved without compromise to their proliferation rate or osteogenic potential, confirming that this is a useful means of storing viable cells for future clinical use.

Programmed cell death (PCD) contributes to the pathogenesis of many diseases including osteoarthritis. The principal method is apoptosis that has a well-defined and very characteristic morphology and biochemistry.

The aim of the present study was examine whether the mechanism of cell death in OA chondrocytes was classical apoptosis.

Rat thymocytes were used as controls since these cells are known to undergo classical apoptosis. Human OA cartilage was obtained from femoral head of patients (50 – 80 years) who were undergoing joint replacement surgery. Pieces of OA samples were processed into paraffin and sections incubated with the following antibodies: M3O, an antibody that recognizes the cleavage of cytokeratin 18 by caspases; annexin V, which recognizes phosphatidylserine “flip-flop” that occurs early in the apoptotic process; bcl-2, a protein whose presence protects apoptosis and c-myc, a transcription factor thought to be associated with apoptosis. To induce apoptosis, some samples were incubated with etoposide and staurosporine.

In sections of thymus we noticed the presence of numerous apoptotic bodies. The number increased when the tissue was treated with etoposide and staurosporine. Some thymocytes were immunopositive for M3O and annexin V, and the number of positive cells increased when treated for 2h with etoposide. Chondrocytes of the articular cartilage showed chromatin condensation and many vacuoles but no fragmentation into apoptotic bodies, even when treated with etoposide or staurosporine. The OA chondrocytes were immunonegative for M3O and annexin-V, even after incubation with etoposide and staurosporine. With respect to c-myc and bcl-2, both non-weight bearing and weight-bearing areas in OA sample showed more positive cells then the thymus. More chondrocytes stained for c-myc in the superficial zone of the articular cartilage in the non-weight bearing, while in the weight-bearing areas it was more in the intermediate zone. On the other hand, there were no differences in the distribution of the cells stained for bcl-2 in the articular cartilage. It is known that some events like the phosphatidylserine flip, caspase activation and apoptotic bodies fragmentation occur quickly during apoptosis, so may be difficult to detect.

The results suggest that some features of classical apoptosis, such as phosphatidylserine flip,caspase activation and apoptotic bodies formation did not take place in OA cartilage. It is known that the molecular machinery for apoptosis is not always present in tissues that are undergoing programmed cell death, which seems to be case for OA chondrocytes.

Aseptic loosening of orthopaedic implants has a major financial impact on the Health Service. The process is thought to be caused by wear particles that are phagocytosed by macrophages and hence stimulate bone resorption via a cytokine response. Previous work suggests that factors inhibiting or enhancing bone resorption act through regulation of the OPG and RANK-L mechanism. The objective of this study was to identify the role of RANK-L and OPG within the cytokine response leading to orthopaedic implant loosening.

Ten samples of cellular membrane obtained during revision arthroplasty surgery were analysed with basic histological staining, immunohistology and polymerase chain reaction (PCR). In vitro studies were also carried out using explanted cancellous bone, to which PMMA particles were added and bone resorbing osteoclastic cells were identified by their Tartrate-Resistant Acid Phosphatase (TRAP) activity.

PCR identified the presence of OPG in all of the periprosthetic samples, with RANK-L shown in 40% of the specimens. Immunoreactivity was shown for CD3, CD68 and RANK-L. In vitro studies confirm that there is an initial burst of inflammatory cytokine activity that then subsequently plateaus.

A balance of RANK-L and OPG regulates bone resorption at the bone/implant interface of implants by stimulating a significant initial inflammatory response which leads to loosening.

Experience has shown that oblique fractures can be slow to heal and this has been attributed to excess shear at the fracture site. We routinely treat fractures with hybrid external fixation. In previous studies, olive wires placed through the fracture site reduced shear and this has improved healing times. When the fracture is oblique in the sagittal plane, anatomical constraints prevent the use of olive wires and a new solution is required.

A sawbone tibia with a distal sagittal plane oblique fracture (70° obliquity) was stabilised with a Sheffield Hybrid Fixator. In a pilot study various methods of fixation were tested and six were chosen for further testing. Since the pull-out strength of threads in the plastic bone was poor, olive wires cut behind the olive were used as a mechanically equivalent model for the push-pull system. Seventy degree steerage pins could not be used so 25° pins were tested instead. Cyclic compressive forces (at 10mm/min) of up to 200N axially and in four off-axis positions were applied using a universal testing machine. Fracture site linear motion in three dimensions was measured using an inter-fragmentary motion device, sampled at 100Hz. A standard frame was tested before and after each adaptation and all six methods were applied sequentially to each model.

The results suggest that: I) Arched wires are effective especially under greater bends, 2) Push-pull wires are effective and provide a minimally disruptive solution, 3) Steerage pins are effective especially at steeper obliquities but this may not always be practical, and 4) Placing a half pin in the distal fragment is beneficial but less effective than the use of 2 transverse half pins acting in a compression system (Hutson technique).

Fractures of the tibia should be reduced as accurately as possible. Fractures opened for internal fixation can be reduced accurately under direct vision, but unstable closed fractures treated by external fixation must be reduced by indirect means. Most surgeons reduce the fracture by manipulation, insert the bone-screws, apply the fixator and then manipulate the fracture again to improve the reduction before locking the fixator. Using this technique it is difficult to obtain a perfect reduction. A poor reduction can prolong healing time and may lead to malunion causing long-term impairment of function. A good reduction lessens the loading imposed on the bone-screws and fixator. We describe a device with which closed tibial fractures can be reduced with a predictable high degree of precision prior to external fixation.

A reduction device, the Staffordshire Orthopaedic Reduction Machine (STORM), was developed. Externally fixed unstable closed tibial fractures reduced by conventional methods (n=37) were compared with those reduced using the STORM (n=41). In the STORM group, the holes for the fixator pins were only drilled once the fracture had been perfectly reduced and no further manipulation was undertaken after the fixator had been applied. Reductions were assessed by measurements of radiographs taken at, and 4 weeks after, fixator removal. All cases were treated with monolateral external fixation.

The STORM significantly improves the precision of reduction of unstable tibial fractures without increasing operating time. Its use obviates the need for reduction joints on external fixators for the tibia.

Previous studies in animal models of limb lengthening have shown a wide spectrum of histopathological changes during distraction phase. Much less is known about the structural response of muscle during the consolidation phase. This study aimed to observe and score changes in morphology, weight, length and maximal perimeter of gastrocnemius during the distraction and consolidation phases.

Thirty two immature New Zealand white rabbits were divided into two equal groups: lengthening and sham. In each group, half of the rabbits were killed at the end of lengthening and half 5 weeks later. A bilateral external fixator was applied to tibia and a mid-diaphysis osteotomy performed. The lengthening rate was 0.4 mm twice daily with an initial delay of 7 days. 30% lengthening was achieved in 4 to 5 weeks. After sacrifice, the whole gastrocnemius was taken from its attachments. Its weight, length and maximal perimeter were measured. At the middle of belly, a specimen 0.5cm in length was taken from the medial gastrocnemius for H& E and Masson trichrome staining. A scoring system was used to achieve a semi-quantitative analysis of the histopathological changes in gastrocnemius.

No abnormal changes were observed in the sham side. Degeneration, atrophy and endomysial fibrosis were all found in the lengthened side. The scores of histopathological changes between the end of lengthening and 5 weeks later showed a decreasing trend, but no significant difference. The weight and perimeter decreased and length increased in the lengthening side. The weight, perimeter and length of gastrocnemius in both lengthening and control sides increased at 5 weeks after the end of lengthening.

Muscular atrophy, as shown by a decrease in weight, perimeter and muscle fibre size, occurred and might be due to the combined effect of continuous muscle stretching and inactivity. Continuous stretching of muscles beyond a certain point produced damage. Some studies reported that damage to muscle fibres, which has been shown as degeneration and fibrosis in this study, can release and activate satellite cells. As myoblast precursors, satellite cells become myoblasts, which proliferate and fuse into the microlesioned areas, regenerating and repairing myofibrils. Also, the immature muscles have more active abilities of proliferation, regeneration, growth and healing. In this study gastrocnemius growth shown by an increase in weight, perimeter and length occurred during the consolidation phase of 5 weeks. The mean scores of histopathological changes in gastrocnemius decreased during consolidation period, indicating some recovery of damage to muscle. It is not clear whether this reflects a normal response, which would have been seen in other studies had samples been taken later or whether it is a unique response of the immature animal.

The aim of this study was to establish the ability of an invasive fibre-optic probe to measure intra-muscular pH, pCO₂, pO₂, HCO₃-⁻, ambient temperature, base excess and O₂ saturation. The secondary aim was to determine the effect of elevation of the limb on these parameters.

Fibre-optic probes were introduced into the anterior compartment muscle of the leg in five volunteers via 16G cannulae. After equilibration the limb was monitored for 11min with the volunteer supine on an examination couch. The limb was elevated to 22cm (Braun frame) and then 44cm for the same time. Subsequently the leg was returned to 22cm and supine. All volunteers followed this set protocol. Continuous recording of all indices was made throughout. Data was stored to a personal computer for analysis.

Similar trends were observed across all subjects for all parameters. The mean pO₂ when lying flat was 27mmHg (S.D.7.4). Elevation to 22cm increased muscle pO₂ to 33 mmHg (S.D. 5.8). Further elevation to 44 cm resulted in a reduction in muscle pO₂ to a level below that measured when supine. When the limb was returned to 22cm the pO2 trend reversed, the level improving. Returning to the supine position the pO₂ returned to the level seen at the start of monitoring.

This novel probe gives reproducible measures of pH, pCO₂, pO₂, HCO₃⁻, ambient temperature, base excess and O₂ saturation. Results indicate that elevation to 22cm improves muscle oxygenation; a height of 44cm seems detrimental. This technique may be applicable in surveillance for compartment syndromes and muscle ischaemia.

Fracture bending stiffness of 15 Nm/° measured in the sagittal plane provides an objective end-point for healing in tibial fractures treated with external fixation (1). Fracture stiffness in other planes has been shown to be significantly different (2). A method for measuring three-dimensional fracture stiffness has been developed (3) and refined. This study describes the results of omni-planar stiffness measurements.

A series of omniplanar fracture stiffness measurements were undertaken on patients with tibial fractures treated by external fixation. The first measurements were performed when the fracture was deemed sufficiently stiff to allow the fixator to be removed safely. These were continued at regular intervals until union, defined as a uniplanar stiffness of greater than 15Nm/° in at least two planes.

Polar stiffness plots were obtained and analysed. The stiffness envelope varied significantly in all planes but the general shape of the polar plot remained the same with successive tests, with an overall increase in stiffness. The polar stiffness measurements were significantly different than concurrent uniplanar measurements; this reflects the difficulty in defining the plane of bending accurately in uniplanar measurements. The fracture configuration and healing fibula had unpredictable effects on the polar stiffness.

The measurement of polar fracture stiffness polar gives new insight into how the mechanical environment of a fracture changes during healing. Fracture stiffness is not uniform and this may have implications on when it is safe to remove the fixator.

Current design guidelines for the front end of motor vehicles aim to reduce tibial fractures but this may be at the expense of an increased risk of injury to the knee itself . The purpose of this study was to describe the type of knee injuries and group characteristics of those sustaining them with a view to initiating a more detailed research project in injuries to the lower limb.

The medical records of all patients aged 16 years and over presenting to the Accident & Emergency (A& E) Department at University Hospital Nottingham with a knee injury sustained in a road traffic accident between April 1992 and December 1998 were identified and reviewed.

In a total of 374 patients, 178 sustained significant knee injuries, requiring admission to hospital. 78% of these sustained a fracture, with fracture of the tibial plateau being most common. 22% of patients sustained ligamentous injury. Almost 50% of patients received operative treatment during the first month after injury.

Current legislation may be responsible for placing pedestrians at more risk from knee injuries. An understanding of the mechanism of knee injury compared with tibial fracture is important and recommendations for prevention of injury can then be instituted.

Cementation is an important part of arthroplasty operations. Recent publication of results of Charnley total hip replacement found a rate of early aseptic loosening of 2.3% at 5 years following surgery across a NHS region. There are possibly many reasons for early loosening but precise reasons are still not fully understood, however, it is felt that cementation technique is very important. There seems to be a number of factors involved such as cement mixing techniques and conditions, physical properties of the cement, cementation and surgical techniques, bone-cement interface as well as bone- prosthesis interface. The purpose of this study was to evaluate the effectiveness of the clinical environment in producing bone cement of predictable mechanical and physical properties, and how those properties compare with published data. The investigation compared samples of bone cement, taken from material prepared and used in surgery with cement samples prepared under controlled laboratory conditions and in accordance with ISO materials testing standards.

During 2000–01, 10 total hip replacements were selected for study. All operations involved the use of CMW1 (DePuy) radio-opaque cement, which was mixed using the Vacumix system. In this cohort, all femoral cementations were performed using an 80g cement mix. After careful preparation of the femoral canal, the scrub nurse mixed the cement in accordance with the manufacturer’s instructions. The cement was introduced into the femoral canal, via a nozzle, using the cementation gun and a pressurizer. Following introduction of cement into the canal, the nozzle and cement contained within, was broken off the gun distal to the pressurizer. Once cured, the cement samples were removed from the nozzle, sectioned, and mechanically tested. Due to this novel sample preparation procedure, the tested cement was expected to exhibit mechanical and physical properties characteristic of the cement present in the femoral canal. Samples of CMW1 (Vacumixed) of similar mass and aspect ratio were produced within the laboratory, in accordance with the manufacturers mixing instructions. PMMA bone cement is a brittle, glassy polymer that is susceptible to stress raisers, such as pores, which can reduce the load carrying ability, which in vivo is predominantly compressive in nature. Published mechanical properties of PMMA bone cement vary somewhat, reflecting the dependence of properties on flaw distribution. The density, which provides a measure of porosity, hardness and ultimate compressive strength of the cement samples was measured and compared.

The surgical samples were found to be very consistent in compressive strength (121 ± 6 MPa), density (1.20 ± 0.02 gcm⁻³) and hardness (23.2 ± 1.6 VHN) and closely matched the mechanical properties of the cement mixed in the laboratory.

This study suggests that for the studied cement and mixing regime, the clinical environment is capable of producing a well-controlled cement product that has reproducible and predictable mechanical properties. Further, the novel sample preparation procedure used suggests that the cement within the femoral cavity should demonstrate equally predictable, mechanical and physical properties.

A research programme has been directed at the mechanism by which car occupants sustain ankle and hind-foot injuries. The severe injuries that are most associated with long term disability and high socio-economic cost have been investigated. Although seat belts and air bags have had a beneficial effect on injuries to most body regions including pelvic, femur and knee injuries, no protective effect has been demonstrated for below knee injuries. Only by understanding the mechanism of injuries to the leg below the knee will it be possible to design improved protection in the future.

Twenty three post mortem human surrogate (PMHS) limbs were impacted using a test set up that was developed to simulate the loading conditions seen in a frontal collision in 3 different positions – A, B & C. The impactor head (5cm x 10cm wide), was instrumented with an accelerometer and linear potentiometer. The impacting force was generated using a bungee-powered sled mounted on steel bearings. Three PMHS legs were tested In Position A (impactor head centred in line with the tibial axis), 9 PMHS legs were tested in Position B (impactor head centred on the anterior tibial margin) and 11 PMHS legs were tested in Position C (impactor head centred 2.5cm anterior to the anterior tibial margin). Active dorsiflexion was simulated through the Achilles tendon and prior to the application of Achilles tension a tibial pre-load (500 to1500N) was applied via a ‘jacking-plate’ applied to the proximal end of the tibia.

During impact testing, bone failure (fractures) occurred at impact loads of 5.7+/−1.9 kN (resultant tibial failure load 6.4+/−1.9 kN) and the following injuries were generated: 9 intra-articular calcaneal fractures; 1 talar neck and 2 talar body fractures; 3 intra-articular distal tibial (pilon) fractures; 2 malleolar fractures; 3 soft tissue injuries and in 3 cases there was no detectable injury. The impact test conditions were replicated with a Hybrid III leg in a first attempt at developing injury risk functions for the dummy.

This study has demonstrated the importance of preload through muscle tension in addition to the intrinsic properties of PMHS specimens in the generation of severe ankle and hindfoot injury.

The purpose of this study was to investigate the influence of ligamentous restraints on first metatarsal (MT1) movements in the context of hallux valgus (HV), the surgical correction of which relies on a sound understanding of factors leading to MT1 deformity. Hypermobility or instability of the first metatarsal at its tarsometatarsal joint (TMJ1) is associated with greater degrees of deformity and also greater risk of recurrence after surgery. Recent anatomical work has shown the importance of the plantar aponeurosis (PA), and the transverse ‘tie-bar’ system (TTB) of the metatarsophalangeal (MPJ) plantar plates and intervening deep transverse inter-metatarsal ligaments in the structure and function of the foot. These ligamentous systems are important in MPJ stability, but may also be important at TMJ1.

Ten normal cadaveric feet were dissected to expose the capsules and ligaments of the MPJs and TMTJs and the PA. They were then mounted in plaster of Paris leaving the MT1, MT2, and their articulations free. A loading fixture was constructed so that loads could be applied to MT1 in the transverse plane to produce moments in flexion, abduction or extension. The movements resulting from a load of 40N were measured relative to MT2 using an Isotrak II (Polhemus, US) magnetic measurement system. The tests were performed with the hallux mobile, fixed neutral and fixed dorsiflexed at the MPJ. After an initial test with all structures intact, the PA and the TTB were severed in random order and the test repeated. “Movement maps” were produced showing the range of motion available in different directions and with different ligamentous restraints.

Movement maps suggest that the TMJ1 behaves as a ball and socket joint with no preferred axis of motion. The contributions of the PA and TTB to stiffness in the sagittal plane are small (about 1° movement). However, the TTB provides significant control of the abduction of MT1. The control afforded by the TTB is particularly important since it can ensure that the PA acts to provide an adduction moment about the TMJ1. The integrity of these ligamentous structures is likely to be important in the success of corrective surgical procedures for HV, where disruption can allow up to 10° increase in MT1-2 angles.

Polymerisation of PMMA results in a volume change resulting from molecular rearrangement. The calculated maximal volume reduction is approximately 7.6%; however, void growth reduces this to 3–6%. The significance of volume reduction is controversial, in particular with reference to void elimination techniques. Whilst the impact of mixing technique on overall volume change is known, little is understood about the dynamic volumetric changes occurring during the crucial time of cement-bone micro-interlock formation. This study aimed to investigate the volumetric behaviour of bone cement during polymerisation.

Polyethylene tubes were modified to simulate the physical and dimensional constraints of the human femoral medullary canal. The tubes were filled with either hand or enhanced vacuum mixed cement and suspended in a water bath. The residual weight of the cement specimen in water was recorded at 60sec intervals for 30 minutes. The dry weight of the cement is known and the immersed weight can be calculated. Archimedes principal allows calculation of the density and thus the volume of the cement mass throughout polymerisation. The specimens were sectioned, stained and analysed to assess sectional porosity.

In no specimen was it possible to demonstrate overall net expansion, however, hand mixed specimens demonstrated a temporary period of expansion during the early exothermic period. Vacuum mixed specimens demonstrated progressive contraction only. Overall volume change correlated closely with sectional porosity.

The overall volume reduction is strongly influenced by porosity. The temporary expansion observed in porous cement specimens must result from temperature driven growth of voids. This expansion occurs during the crucial period of cement-bone micro-interlock formation, and may therefore enhance attempts at pressurisation. Conversely, progressive volume reduction, as seen with low porosity cement, may impede micro-interlock formation. Successful cementation using vacuum mixed cement may therefore be solely dependent on adequate cement pressurisation.

The restoration of pain-free stable function in gleno-humeral arthritic cases in various situations such as rotator cuff deficiency, old trauma and failed total shoulder arthroplasty is a challenging clinical dilemma. The Bayley-Walker shoulder has been designed specifically for very difficult cases where surface replacement devices do not provide sufficient stability. This device is a fixed-fulcrum reversed anatomy prosthesis consisting of a titanium glenoid component with a CoCrMo alloy head that articulates with an UHMWPE liner encased in a titanium alloy humeral component that has a long tapered grooved stem. The centre of rotation of the Bayley-Walker shoulder is placed medially and distally with respect to the normal shoulder in order to improve the efficiency of the abductor muscles. An important problem in devices of this type is obtaining secure and long-lasting fixation of the glenoid component. The glenoid component relies on fixation through the cortical bone by using threads, which protrude through the anterior surface of the scapula at the vault of the glenoid. It is HA coated for subsequent osseointegration. The purpose of this study was to investigate fixation of the glenoid component.

A 3D finite element model of the glenoid component implanted in a scapula was analysed using Abaqus. The implant was placed in position in the scapula, with the final 2–3 screw threads cutting through the cortical bone on the anterior side at the vault of the glenoid due to the anatomy in this region. The analysis was performed for two load cases at 60° and 90° abduction. A histological study of a retrieval case, obtained 121 days after implantation, was also conducted.

The FEA results showed that most of the forces were transmitted from the component to the cortical bone of the scapula, the remaining load being transmitted through cancellous bone. In particular the area where the threads of the glenoid component penetrated the scapula showed high strain energy densities. Histology from the retrieved case showed evidence of bone remodelling whereby new bone growth resulting in cortical remodelling had occurred around the threads.

Both the FEA and histological study show that fixing the component at multiple locations in cortical bone may overcome the problems of glenoid loosening associated with constrained devices. The Bayley-Walker device has been used on a custom basis since 1994; 81 Bayley–Walker shoulders for non-tumour conditions and 43 Bayley-Walker glenoid components have been used in association with a bone tumour implant, with good early results. Radiographically, radiolucencies have not been observed and overall the comparisons with the original Kessel design are positive.

It is generally appreciated that the internal structure and external shape of living bone adapt to mechanical stimuli according to Wolff’s law. However, the precise details of bone adaptation to external forces are not fully understood and there has been no previous investigation of the association between specific loading conditions and the skeletal architecture of a particular anatomical area using case-specific observations in a group of individuals. The aim of the present study was to investigate a previously unreported correlation between the maximum wrist joint reaction force and the volar tilt angle of the distal radius using parameters radiographically obtained parameters from normal wrist joints.

Using free body analysis of the forces acting on the distal radius for the loading condition that corresponds to the lift of a weight using the supinated hand, the wrist joint reaction force F and the angle formed between the vector of F and the long axis of the radius have been expressed as a function of the lifted weight, the lever-arm of the wrist flexor tendons and that of the lifted weight. Measurements of the volar tilt angle of distal radius and the lever-arms of the flexor tendons and the lifted weight were performed from lateral wrist radiographs of 30 normal wrists. Subsequently, using the equations obtained from free body analysis, the maximum wrist joint reaction force F and the angle that the latter forms with the long axis of the radius were calculated for each the cases. Statistical analysis compared the angle of the maximum wrist force and the volar tilt of the distal radius (two-tailed paired t-test) and correlated (a) the angle of the maximum wrist force and the volar tilt angle and (b) the maximum joint reaction force and the volar tilt angle.

Results showed no significant difference (p=0.33, 95% confidence interval −0.64° to 0.22°) but a statistically significant correlation (R² = 0.74, r = 0.86, p < 0.001) between the angle of the maximum wrist force and the volar tilt angle of the distal radius. Additionally, an inverse relationship between the volar tilt angle and the magnitude of the maximum wrist force (R² = 0.71, r =−0.84, p< 0.001) was found.

These observations may explain the mechanism of the phylogenetical development of the volar tilt angle and support the ‘minimum effective strain’ theory of adaptive bone remodeling1. The importance of accurate restoration of the volar tilt during treatment of distal radius fractures, especially in wrists that are normally characterised by a low volar tilt angle, is also emphasized by the results of the present study.

Clinical implantation represents the ultimate experiment of any component and often demonstrates areas of strengths and weaknesses not predicted from in vitro testing. Mobile bearing knees incorporate an additional articulating interface between the flat distal PE insert and a highly polished metal tibial tray. This can allow the proximal interface to retain high conformity whilst leading to reduced stresses at the bone – prosthesis interface by permitting complex distal interface compensatory motion to occur (rotation and/or translation). Retrieval reports on many of the new generation of mobile bearing implants remains scarce. This study presented a retrieval analysis of 9 mobile bearing inserts that had be in situ for less than 24 months.

Nine cemented mobile bearing implants (6 AP Glide, 1 LCS, 1 MBK and 1TRAK) were received into our Implant Retrieval Program. The femoral component, tibial tray and PE insert were macroscopically examined under a stereo-zoom microscope for evidence of damage. The PE inserts were graded for wear based on optical and SEM assessments. The proximal and distal surfaces of the PE inserts were subsequently assessed for surface roughness following ISO 97 (Ra and Rp) using a Surfanalyzer 5400 (Federal Products, Providence, RI). Virgin, unused PE inserts were analysed and served as a comparison to the retrieved implants.

Time in situ time for these implants ranged from 6 months to 24 months (mean 18.6). The implants were revised for instability and pain (AP glide) or dislocation (TRAK). Damage to the femoral components, in general, was minimal with some evidence of a transfer film of PE. The proximal surface of the tibial trays presented evidence of PE transfer as well as some scratches but in general were intact. The proximal PE and distal PE articulating surfaces demonstrated significant areas of damage due to third body wear which was identified on EDAX to be PMMA. Areas of burnishing were also present at the proximal and distal interface. The damage, in part, correlated with the complex kinematics of each design.

Metacarpophalangeal (MCP) arthroplasty usually involves the fitting of a silicone spacer, commonly Swanson prosthesis, but more recently the Sutter prosthesis has been introduced.

Four Sutter MCP prostheses, two each sized 30 and 40, were removed from the right hand of a female patient. The patient aged 61 years ate revision, had longstanding rheumatoid arthritis. Using a single station finger stimulator¹ two Sutter size 50 MCP prostheses were tested. This stimulator ran at a speed of 100 cycles per minute. During each of these cycles, which flexed the test prosthesis through a 90° arc of motion, the load across the test prosthesis varied between 10N and 15N after 3000 cycles, the stimulator applied a static ‘pinch’ load and the whole combined load cycle began again. Ringer solution heated at 37°C was used as a lubricant. Clinically, the prostheses had been implanted for 53 months. All four had fractured at the junction of the hinge and distal stem. In the simulator tests the Sutter size 50 prosthesis managed just over 10 million cycles of flexion-extension, including over 3300 ‘pinch’ loads before fracture occurred, at the junction of the distal stem and hinge. The second prosthesis fractured in the same manner after 5.3 million cycles of flexion-extension.

These are the first reported in vitro results of fracture of Sutter prosthesis as well as the first paper to state the site of ex vivo fractures of Sutter prostheses. A computer model described in a recent paper ² indicated that failure of the Sutter prosthesis should occur at the central hinge region. Clearly the in vitro results and the ex vivo experience disagree with the computer model. McArthur and Milner ³ have shown clinically that the Swanson joint appears to be superior to the Sutter implant, a result confirmed elsewhere4. The finger stimulator has previously caused fracture of Swanson pros-thesis in a time and a manner comparable with surgical experience¹. Therefore another correlation with ex vivo results, but testing the Sutter prostheses has further validated the finger simulator.

Infection around implanted biomaterials in humans is a major healthcare issue and current ability to effectively prevent and treat such infections using antibiotics is limited. The hypothesis of the study was that surface charge could be manipulated to a positive state and thus moderate bacterial adhesion to the implant. The surface charge was manipulated by creating a galvanic cell using a zinc strip in a standard suction drain.

Adhesion of Staph. aureus and Staph. Epidermidis to stainless steel and titanium implants in vitro and in vivo was quantified by sonication and log dilution technique. The response to this surface manipulation of charge varied for both the bacterial species and the type of metallic implant. In vitro studies produced an 88% reduction in Staph. aureus adhesion to stainless steel and a 36% reduction in adhesion to titanium. However Staph. epidermidis showed an increased adhesion to stainless steel (Log 1.81 ± 1.12 in vitro) and to titanium (log 1.80 ± 0.12). Staph aureus demonstrated a log increase of 1.56± 0.09 in adhesion to titanium in vivo while Staph. epidermidis generated a log increase of 3.97± 0.10 in adherent bacteria.

In this experiment we have shown that alteration of the electrochemical environment around an implant influences bacterial adhesion. While our technique is not therapeutically viable, further manipulation of surface charge of an implant is possible using other electroactive materials. This may be explored in the prophylactic treatment of implant infection

There has been speculation as to whether the outcome of revision total knee arthroplasty (TKA) is as successful as primary TKA. The purpose of this study was to assess patient outcomes following revision TKA and compare them to patient outcomes following primary TKA.

This study collected data prospectively from patients operated upon by one surgeon using one prosthesis in each group. Patients completed SF12 and WOMAC questionnaires pre-operatively and at six and twelve months post-operatively. In the primary TKA group there were 84 patients. In the revision TKA group there were 60 patients. Statistical analysis was performed using paired and unpaired t-tests.

Results showed that the improvements in SF12 physical scores and WOMAC pain, stiffness and function scores in both primary TKA and revision TKA patients were statistically significant (p < 0.0001). There was no significant difference in the magnitude of the improvement in SF12 physical (p = 0.7145) and WOMAC pain (p = 0.0902), stiffness (p = 0.1557) and function (p = 0.3152) scores between the primary and revision patients following surgery.

The mental scores of patients in both groups showed no significant difference following surgery (Primary p = 0.823, Revision p = 0.7095).

The findings show that primary and revision TKA lead to a comparable improvement in patient perceived outcomes of physical health parameters.

However, there is no significant improvement in patient perception of mental health.

Controversy exists as to whether the biomechanical properties of a 360 lumbar fusion are influenced by the order in which the anterior and posterior components of the procedure are performed.

The fusion technique used Magerl screws to effect the posterior fusion and a Syncage implant (Stratec) to effect the anterior component of the fusion.

Isolated motion segments from calf spines were tested in each of two groups of five. In the first group the posterior fusion was performed first and in the second group the anterior fusion was performed first. Loads were applied as a dead weight of 2Nm in each range of movement of the spine (flexion/extension, lateral flexion and rotation). The range of movement was measured using the Qualisys motion analysis software linked to a set of five cameras, using external marker clusters attached to the vertebral bodies. Each motion segment was tested prior to instrumentation, post anterior or posterior instrumentation and with both anterior and posterior instrumentation.

Ranges of movement following 360 instrumentation were increased in all planes tested when posterior fixation was performed first; flexion/extension 26% v 55% (p=0.020), lateral flexion 18% v 34% (p=0.382), and rotation 18% v 73% (p=0.034).

It was concluded that posterior fixation should not be performed prior to anterior fixation as this results in a significant loss of stability in both flexion/extension and rotation

The inhibition of neural input by infiltration of local anaesthetic around the operation site prior to the trauma of an operation may reduce subsequent pain post-operatively. Prevention of the normal phenomenon of central and peripheral sensitisation in the nervous system stops the post operative hypersensitivity state that manifests as a decrease in the pain threshold at the site of injury. The underlying clinical principle is for therapeutic intervention to be made in advance of the pain rather than as a reaction to it ¹. We performed a prospective double blind randomised clinical trial to measure the effect of pre operative infiltration of local anaesthetic around arthroscopy wounds compared to post-operative infiltration on post operative pain relief.

Thirty six patients undergoing day case unilateral knee arthroscopy between October 2000 and March 2001 were studied. All patients gave written informed consent. They were randomised into 2 groups using block randomisation to ensure equal group sizes. The sealed envelope technique was used. The pre-operative group had 10ml 0.25% bupivicaine infiltrated around the arthroscopy portal site following induction of general anaesthesia (G.A.), the post-operative group received 10ml 0.25% bupivicaine after the procedure but before reversal of the G.A. The injection technique and G.A. used were standardised. Pain was assessed using a 10cm Visual Analogue Score (VAS) at pre-operative, 1, 2 and 24h post-operative. At each assessment the patients were blinded to the previous scores that they had submitted. Oral analgesic use in the post-operative 24 hours was also recorded.

There were 18 patients in each group. Demographic details did not differ between the 2 groups. One patient in the post-operative group was excluded, as intravenous sedation was required in recovery due to an extreme anxiety state. The mean Visual Acuity Pain Scores (VAS) were lower in the post-operative group (1.3) compared to the pre-operative group (1.58) at pre-operative assessment. However this difference was not statistically significant (p =0.5607). At 1h post op the mean VAS in the post op group was 1.58 and in the pre op group 2.59 (p =0.18). The mean VAS at 2h post op in the pre op group was 1.76 compared to 1.82 in the post op group (p =0.9932).

At 24h the pre op group had a lower mean VAS (2.25) than the post op group (2.4). This difference was however not statistically significant (p =0.7418).

Analysis of the postoperative analgesia requirement in both groups failed to reveal a statistically significant difference (p =0.3965). In day case knee arthroscopy under general anaesthesia there is no beneficial role in the use of pre-emptive local anaesthetic infiltration around the arthroscopy portal sites as compared to post-operative infiltration.

The use of crude mortality and morbidity data to assess the outcome from surgical intervention can be both dangerous and misleading. Furthermore, differences in outcome when comparing differing units or surgeons may be explained merely by variations in case mix and the type of surgery.

In recent years there have been a number of attempts to devise a reliable method for assessing the outcome from surgical intervention. In the general surgical setting, the POSSUM system has proved to be the most reliable and accurate of all scoring systems so far devised. It is widely applicable in other specialities as it allows comparison based on the patient’s physiological status and the magnitude of surgery. It could be used in any hospital, in elective and emergency operations. The present study attempted to validate the application of this new method of assessing the outcome after orthopaedic surgery.

All consecutive patients admitted to the orthopaedic wards in a district general hospital during a 12 month period in which orthopaedic surgery was performed on a non-day case basis were assessed using the new orthopaedic POSSUM system. POSSUM is an acronym for Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity. POSSUM is a two-part system that scores both physiological and operative factors. It is developed of multivariate discriminate and logistic regression analysis of 62 variables reduced to: * 12 factors, 4 grade physiological score and * 6 factors, 4 grade operative severity score. When these are combined, a numerical estimate of both mortality and morbidity is obtained. Mortality prediction for individual patients was estimated using this equation: Log [risk − (1 − risk)] =−7.04 + (0.13 physiological score) + (0.16 operative severity score)

During the 12 month period, 2326 patients underwent orthopaedic surgery. 44% were in elective setting, 56% were in emergencies. Using the POSSUM logistic regression equations yielded an overall predicted mortality of 53 patients (versus 51 observed) and a predicted morbidity of 254 patients (versus 252 observed).

The present study indicates that orthopaedic POSSUM is accurate in assessing outcome after an orthopaedic operation and can be used as an audit aid to assess the quality of surgical care.

Therapy against Methicillin resistant Staphylococcus aureus (MRSA) infection is mainly restricted to the glycopeptide agents (vancomycin and teicoplanin), which require parenteral administration. At present oral antibiotic therapy against MRSA infection is not available. Linezolid is a recently introduced oxazolidinone synthetic antibiotic which acts by inhibiting the initiation of bacterial protein synthesis. It is effective against MRSA, glycopeptide resistant enterococci and all pneumococci irrespective of their penicillin or macrolide resistance. It has excellent oral bioavailability however, there are no data on the penetration of linezolid into osteoarticular tissues. This aim f this study was to measure the concentration of Linezolid in osteoarticular tissues after oral and intravenous administration.

Ten patients undergoing primary total knee replacements for osteoarthritis or rheumatoid arthritis were included in the study. Linezolid was given orally 600mg BD dose for 2 days prior to operation and a final IV 600mg dose 1h before induction on the day of operation. Intra-operatively at 30min after induction, blood, synovial fluid, synovium, muscle and bone samples were collected, processed and assayed for Linezolid concentration. The assay was performed by High Performance Liquid Chromatography (HPLC) method at Antimicrobial Research Laboratory, Westmead Hospital, Bristol.

High concentrations of Linezolid, above the Minimum Inhibitory Concentration (MIC≤ 4) were obtained all sites. Mean (± SD) concentrations for different tis- were: serum 23.0 (6.5) mg/L, synovial fluid 20.1 .4) mg/L, synovium 18.0 (5.6) mg/kg, muscle 18.5 (6.6) bone 8.5 (3.9) mg/kg

Treatment of Methicillin resistant Staphylococcus (MRSA) infections in bone and native or pros- joints is complex and costly. It requires prolonged parenteral and oral antibiotic combination therapy in addition to aggressive surgical debridement. The MICs Linezolid for staphylococci, pneumococci and streptococci are in a range from 0.5 to 2 mg/L whereas MIC enterococci is constant at 4mg/L. A two to six fold increased bioavailability of Linezolid was observed compared to its desired MIC. This study indicates that Linezolid penetrates osteoarticular tissues in sufficient concentration. Linezolid may prove to be an effective or intravenous therapy for serious bone and joint infections with multi-resistant gram-positive bacteria.

12 GPs were invited to take part in a study in which the GPs would undertake training in out-patient techniques, to determine suitability of patients for arthroscopic surgery. The GPs would undertake to counsel the patients regarding the procedure itself and the post operative rehabilitation. They were then referred by means of a set referral form which included specific guidelines which allowed patients to be put directly onto the consultant’s waiting list. The patients would then be sent for surgery directly and be seen immediately pre-operatively by the operating consultant and consented. This group of direct access arthroscopy patients (36) were compared to a contemporaneous consecutive series of patients who had been referred in the normal manner and were undergoing operation at the time of the study period (October 1998 to April 2000.

In the group of patient submitted for direct access arthroscopy three patients had improved such that when they were offered admission dates they declined. A further three patients were deemed unsuitable for direct access arthroscopy and the referral was rejected by the consultant. Two patients declined three separate admission dates and were discharged, and a final patient did not attend his admission date. This left 27 patients who were admitted for direct access arthroscopy service. Of these, one patient was cancelled pre-operatively by the consultant as she had recently been admitted for investigation of cardiac abnormalities procedure and was therefore considered unfit for day case general anaesthetic procedure. Of the 26 patients who underwent arthroscopy all were discharged home the same day, and reviewed in the out-patient clinic at six weeks, and they were asked to complete a Patient Satisfaction Questionnaire, and were discharged from further review at that time.

When compared to a contemporaneous group of patients who had undergone arthroscopic surgery via the routine referral procedure, the group of patients admitted via the direct access route waited on average ten weeks (range 6 – 12) from GP consultation and referral to operation date. This compared to 41 week for the combined total out-patient and in-patient waiting times for the routine access group (range 18 – 132 weeks). Findings at arthroscopy were similar in the two groups with mostly meniscal lesions (18/26 direct access group compared to 15/26 routine access group). The therapeutic operation rate, i.e. procedures beyond simple diagnostic arthroscopy were undertaken, was high in both groups, 68% of the direct access group and 72% of the routine access group. Pre-operative diagnosis accuracy by the GPs was significantly higher in the direct access group of referrals. 65% of direct access referrals had the correct diagnosis made by the GP in the referral compared to 18% of correct diagnosis in the group undergoing routine referrals. Post operative recovery in terms of return to work , return to activities of daily living and discharge from clinic was the same in the two groups. Patient satisfaction was comparable in both groups.

In conclusion direct access arthroscopy reduces significantly the time the surgery and the number of visits by patients to primary or secondary care physicians. GP diagnostic rates were comparable to previously reported figures for registrar/middle grade pre-operative diagnostic rates for patients undergoing knee artrhoscopy. There was a high therapeutic operation rate suggesting few, if any inappropriate procedures were undertaken. The direct access arthroscopy service requires considerable time on the part of the consultant in both setting up the study and training the GPs to a reasonable standard and monitoring referrals and undertaking pre-operative screening of patients awaiting arthroscopy. There was a high inappropriate referral rate in that only 26 patients out of the 36 referred eventually underwent arthroscopic surgery. Although feasible we feel that direct access knee arthroscopy service needs refinement if it is to continue. We intend to introduce an orthopaedic practitioner who will accept referrals from GPs and then screen patients before placing patients on the consultant’s inpatient waiting list. Also the mechanism of extra lists needs to be put in place to ensure direct access patients do not “jump the queue” of patients who are already awaiting arthroscopic surgery.

To clarify the normal range of articular cartilage volumes of the patella and femur in the human knee joints of healthy adults using three-dimensional magnetic resonance imaging and to analyze the correlation of the articular volumes with the background characteristics.

Fifty seven knees of 57 healthy volunteers aged from twenties to forties (30 males and 27 females), who had no past history of joint disease or trauma in the legs, were imaged by a fat-suppressed three-dimensional sequence (SPGR; 1.5T GE; Horizon LX 8.2.5) The obtained data were analyzed by 4 examiners independently with a computer workstation, and a average of the four was adopted as the articular volume. Analyzed characteristics factors of the volunteers were: age, body weight, height, leg length, foot size, circumference of the thigh and lower leg, quadriceps angle, foot angle, body-mass index, and general laxity.

The mean articular cartilage volume was 7.2 +- 1.6 ml. It was significantly larger in males than in females. Concerning the relationship between the volume and the characteristic factors, there was a significant correlation of the cartilage volume with the foot size in males (r=0.47), and with height, leg length and foot size in females (r=0.53, 0.60, 0.60, respectively), but no significant correlation with the other factors.

Conclusion. The articular cartilage volumes of the patella and femur was 7.2+- 1.6 ml. The size of skeletal structure, especially the skeletal size of the lower extremity, were assumed to be important factors in estimating cartilage volume.

Presently, many instruments exist for assessing both patient - and surgeon-based satisfaction after joint replacement, including both generic (measures of general health status) and disease specific measures. As such, the US PORT study (1995) recommends use of both the WOMAC and SF-36. However, this means that studies need to incorporate at least these two lengthy questionnaires into protocols, which increases the pressure on patients for both time and difficulty, but also introduces some duplication of data.

The SF-36 has been successfully reduced and validated to a 12 item questionnaire (SF-12) which can be used as a summarised generic health score. It would be of great benefit if a reduced version of the WOMAC could be derived to give a similar summarised disease-specific measurement tool.

To derive and assess the validity of a reduced function scale of the WOMAC for patients with osteoarthritis of the hip and knee.

All unilateral data from 12 centres world-wide (UK US Canada and Australia) involved in an international, multi-centre outcome study for patients undergoing TKR were included for analysis. The reduced scale was derived from pre-op and 3 month post op data using a combination of data-driven analysis and purely clinical methods. The reduced WOMAC was then extensively validated in three key areas; validity, reliability and responsiveness using 12 month post-op data from the study and data from the Medicare Hip Replacement Study.

Data from 898 patients pre-operatively and 806 patients at 3-months were used for the data driven section of analysis. For the clinical section, 30 members of the orthopaedic community were surveyed as to their opinions of which items should be retained in the reduced version of the scale. These results were then combined to produce a reduced function scale of 7 items to be used in conjunction with the 5-item pain scale. The questions remaining in the scale (and their original number in the scale) were: 2) ascending stairs, 3) rising from sitting, 6) walking on flat, 7) getting in/out of car, 9) putting on socks/stockings, 10) rising from bed and 14) sitting. This reduced scale was then scrutinised to ensure it’s validity (both construct and content), reliability (both internal consistency and reproducibility) and responsiveness (using Standardised Response Means). When examining 12 month data the reduced scale compared favourably with the full scale both overall, and when sub-divided by age, sex and country. It’s construct validity was confirmed by significant positive correlation with the SF-36 physical component score, the knee society function score, the Oxford knee score, and for the hip data, the Harris hip score and SF-12 physical component score. Cronbach’s alpha was consistently high (α> 0.85) with the reduced scale, showing it to be reliable, and the SRM’s indicated that the reduced scale may even be better at detecting change than the full scale.

This reduced WOMAC has been successfully derived and validated for use as a summarised and more practical version of the full WOMAC scale.

It was aimed to investigate the isolated effect of hydrostatic pressure on chondrocyte metabolism. Chondrocytes obtained from bovine metatarso-phalangeal joints were cultured in cylindrical 2% agarose gels. A special apparatus which was designed and constructed, allowed the application of hydrostatic pressure of either 2 MPa or 5 MPa on the chondrocytes for 4 hours either in a pulsatile (1Hz) or a static manner. Changes in the syntheses of glycosaminoglycan (GAG) and DNA during and after the application of the hydrostatic pressure were analysed with ³⁵S-sulphate and ³H-thymidine incorporation, respectively. Radiolabelling was carried out for the following conditions: (a) 4 hours during the application of hydrostatic pressure; (b) 4 hours and (c) 20 hours immediately after the application of load. In addition, the experiments were carried out at 2 days, 7 days and 14 days after embedding the chondrocytes in agarose gels. Static hydrostatic pressure of 5 MPa caused a significant increase by 13% on average in the GAG synthesis during the load application on Day 2 7 and 14 (p < 0.05). On the contrary, pulsatile pressure of 2 MPa caused a significant decrease by 17% in the GAG synthesis measured at 20 hours after the loading on Day 14 (p < 0.01). In addition, there was a significant decrease by 29% in the DNA synthesis measured at 4 hours after the pulsatile loading of 5 MPa on Day 7 (p < 0.01). The results suggest that hydrostatic pressure alone, which causes no cell deformation, can affect the GAG synthesis and proliferation of chondrocytes. In addition, the effect of hydrostatic pressure on the chondrocyte metabolism varies according to the regimes of loading and with the period of cell culture.

The purpose of this study is to evaluate the relationship between the clinical results and the angle of the reconstructed ligament measured radiographically.

We also describe the comparison of the results by the fixation technique of the femoral tunnel. We retrospectively evaluated 90 patients who had arthroscopy assisted ACL reconstruction using middle-third middle-third bone patellar tendon autograft. There were 67 men and 23 women. Their average age at surgery was 23.9 years. The average follow up periods was 28.0 months. We used interference fit screw for grafted ligament fixation of the femoral and tibial tunnel. 71 patients received inside out technique and on 19 patients outside in technique as for the fixation of the femoral funnel.

The lateral angle and A-P angle of the reconstructed ligament were measured roentgenographically. Data from KT-2000 arthrometer testing with side to side difference and Lachman test were used to assess postoperative anterior knee laxity.

Pivot shift tests were also used for rotational knee laxity. Data from roentgenograms reflected the correlation with clinical testing.

Mean value of the side to side difference was 1.3mm. In pivot shift test, the average lateral angle of the reconstructed ligament of negative group was 73.2o , while positive group was 77.2 o , it was statistically significant. The average lateral angel and A-P angle of the reconstructed ligament with inside out technique group was larger than those of outside in technique group.

Recent recommendations placing the tibial tunnel more posterior results in a lower incidence of graft impingement, but we found a relationship between the angle of the reconstructed ligament and rotational stability of the knee.

Anterior-posterior stability can be obtained by achieving posterior placement of the reconstructed ligament. More vertical graft angle caused by posterior placement of tibial tunnel should affect rotational stability. Inside out as the way of fixation technique for the femoral tunnel showed a tendency of more vertical graft angle.

The purpose of this study is to clarify optimal timing of anterior cruciate ligament (ACL) reconstruction from the point of view of meniscus injury.

One hundred thirty-five ACL injuries (under 40 years of age) were analyzed in this study. All knees had undergone primary reconstruction without other ligament injury, and follow-up arthroscopy. ACL reconstruction was performed by the semitendinosus and gracilis method. The rehabilitation protocol was based on that of Shelbourne. Cases were divided into 4 groups by the period from injury to reconstruction. Nineteen knees were of the acute phase, which is within 1 month from the injury to reconstruction. Thirty-one knees were of the subacute phase, which is from 1 month over to reconstruction. Thirty-one knees were of the subacute phase, which is from 1 month over to 3 months from the injury to reconstruction. Forty knees were of the subchronic phase, which is from 3 months over to 1 year from the injury to reconstruction. Forty-five knees were of the chronic phase, which is over 1 year from the injury to reconstruction. We compared arthroscopic findings as well as clinical follow-up results of each phase.

The rate of lateral meniscus injury were 84% in the acute phase, 39% in the subacute phase, 58% in the subchronic phase, and 51% in the chronic phase. The rates of medial meniscus injury were 32% in the acute phase, 29% in the subacute phase, 53% in the sub-chronic phase, and 60% in the chronic phase. Horizontal tear and degenerative tear of the lateral meniscus were increased with time. Osteoarthritic change at follow-up arthroscopy was observed 3 knees in the acute phase, 4 knees In the subacute phase, 8 knees In the subchronic phase, and 13 knees in the chronic phase. There was no difference between clinical results of our ACL reconstruction in the acute phase and chronic phase.

ACL reconstruction in the acute phase was the effective method for preventing secondary osteoarthritis after medial meniscus injury.

Clinical investigations and tests need to be validated by studying their inter-observer and intra-observer errors, but there has been no documentation of such verification in diagnostic knee arthroscopy. We performed a prospective study to find out to what extent the findings in knee arthroscopy differ between two different surgeons.

Two senior specialist registrars (M.S. and A.J.) who took part in this study worked with the senior author (ACW) for a period of eight and seven months respectively. A total of 78 knee arthroscopies admitted from routine waiting list were studied. The specialist registrar first performed arthroscopy when the supervising consultant stayed away from the operating room. His findings were recorded on a proforma by an independent third person before the consultant returned to the operating room and repeated the EUA and arthroscopy without prior knowledge of the trainee findings. Findings from the consultant arthroscopy were then recorded separately on the same proforma.

The following findings were recorded:

Examination under anaesthesia

The inter-observer variations in diagnostic knee arthroscopy were found to be high. Given the seniority and experience of the two trainee senior registrars involved in the study, and allowing for the Hawthorne effect, the results of the study cast doubt on this procedure being performed un-supervised. It also questions the validity of any therapeutic intervention based on the findings of un-supervised arthroscopies.

The aim of this longitudinal study is to compare the clinical outcomes of endoscopic ACL reconstruction with either a 4-strand HT or PT autograft over a 5-year period.

90 patients with isolated ACL rupture received PT autograft and 90 received HT autograft were studied annually for 5 years. Assessment included the IKDC Knee Ligament Evaluation, KT1000, Lysholm Knee Score, thigh atrophy, kneeling pain, hamstring pain and radiographs.

The median Lysholm Knee Score was 96 for the PT group and 95 for the HT group. No significant difference was found for subjective knee function, overall IKDC assessment, Xray findings, manual ligament KT1000 instrumented testing, graft rupture or contralateral ACL rupture. There was an increasing incidence of fixed flex-ion deformity seen in the PT group. There was no difference in the requirement for subsequent surgery. The incidence of kneeling pain at 5 years was significantly higher in the PT group.

Endoscopic reconstruction of the ACL utilizing either autograft can restore knee stability and is menisco protective despite a high level of sporting activity. We did find a worrying trend towards an increasing incidence of fixed flexion deformity with time in the patellar tendon group. Kneeling pain also remains a persistent problem in this subgroup.

This study set out to determine the incidence of avulsion of the posterior horn of the lateral meniscus in isolated Anterior cruciate ligament injuries.

Anterior cruciate injuries are often associated with meniscal injuries and a number of different patterns of injuries are described. Although avulsion of the posterior horn of the lateral meniscus has been reported in combined ACL/MCL injuries this has not been reported in isolated ACL injuries. We examined 25 consecutive patients who had ACL ruptures and recorded the presence or absence of an avulsed posterior horn of the lateral meniscus. The mechanism of injury was also recorded. We found 6 patients (24%) with avulsion of the posterior horn of the lateral meniscus from its tibial attachment. All these patients had an external rotation injury rather than a valgus type injury.

Avulsion of the posterior horn of the lateral meniscus is a relatively common finding in ACL injury. If this injury occurs the normal load sharing function of the meniscus may not be present and this may be part of the explanation for the development of degenerative change in the ACL injured knee.

The purpose of this study was to establish the return of function to an unstable knee following stabilization of the anterior deficient cruciate ligament.

15 consecutive cases of chronic anterior cruciate ligament rupture with instability were studied prior to stabilization by patellar bone-tendon-bone autograph, and again at three months post-operation and at one year post stabilization. There were two women and thirteen men in this study. All operations were performed by one of the authors (John Fleetcroft).

Peak torque, total work and average power were studied at 90°/sec and 120°/sec.

Three patients had unusually low contralateral flexor power at 120°/sec pre-operatively, these measurements were excluded from the 120°/sec results.

Our findings show an initial decrease of strength three months postoperatively; on the extensors more than on the flexors.The flexors recovered faster than the extensors.

Extensor function showed a deficit of 13% at both speeds pre-operatively. Three months following surgery this has increased to an average of 33.7% at 90°/sec and 22.8% at 120°/sec. At one year the deficit had decreased dramatically to 2.2% at 90°/sec and 0.14% at 120°/sec.

Flexor function at 90°/sec showed a deficit of 6.4% pre-operatively, 15% at three months and 1.7% at one year. At 120°/sec, pre-operative flexor deficit was 3.1%, +0.16% at three months and +4.4% at one year.

These tests demonstrate the return of function to unstable cruciate deficient knees, an important observation for those wishing to return to sport.

Defects of the anterior cruciate ligament have been treated surgically with intra- and extra-articular procedures since several decades, either as direct repair or using autografts of the hamstring or patella tendon in open or arthroscopic operations. On the other hand there are studies about successful results of conservative treatment available, too.

Casteleyn et al (1) reported about the follow up of at least five years (mean 8.5 years) of 109 patients which excluded professional and high level athletes. The evaluation of their symptoms with an IKDC score showed 23% in grade A and 50% in grade B out of four possible grades with an incidence of 5.4% secondary ACL surgery.

In an editorial article about anterior cruciate ligament reconstruction Dandy et al (2) reviewed the results of several studies about intra- and extra-articular procedures, which examined pivot-shift and restriction of activity.

Johnson et al (3) found in 87 patients with bone-patellar tendon-bone reconstruction and a mean follow up of 7.9 years 26% positive pivot shift and 25% of the patients had unrestricted activity. Sandberg et al (4) reviewed a similar group of 89 patients after seven years with 11% positive pivot-shift and 24% unrestricted activity.

In comparison to these results extra-articular procedures show a higher incidence of pivot-shift and lower levels of unrestricted activity; Odensten et al (5) report 59% clinical instability four years after Ellison procedure and 39% positive pivot-shift with only 44% unrestricted sport activity at six years after MacIntosh operation.

Over the last years extra-articular procedures were abandoned in favor for intra-articular operations.

Today bone-patellar tendon-bone grafts are widely used for these repairs.

Clancy et al (6) and Butler et al (7) have shown in animal studies a decrease of strength and mechanical properties postoperatively during an initial period of revascularisation and remodelling.

Grontvedt et al (8) look at these properties in their study about the effects of the use of a ligament augmentation device by isokinetic testing on a Biodex™ system. They measured peak torque and total work and found a deficit in the quadriceps strength in comparison to the uninjured knee of 25% at six months, 15% at one year and 10% at two years. The hamstrings improved to equal levels already after six months.

The aim of our study was to assess the mechanical properties torque, total work and average power of the hamstrings and quadriceps in order to evaluate the progress of the patients postoperatively including the above mentioned initial decrease in strength. The testing was performed with a Cybex™ machine preoperatively as well as three and twelve months postoperatively.

We tested patients who had a bone-tendon-bone anterior cruciate ligament reconstruction performed between March 1998 and January 1999. It was only a limited time window available for this study and therefore we could conduct the tests only on 15 consecutive patients. We tested two women and 13 men. Their mean age was 38.4 years (21 to 50). Injuries of the anterior cruciate ligament were confirmed by both clinical and arthroscopic examination. Indications were clinical instability, pain and / or swelling during sport or other physical activity and / or other relevant history (knee gives way). All the operations were arthroscopic assisted procedures. They were performed by only one surgeon (J P Fleetcroft). The graft was obtained from the middle third of the patellar tendon and fixed with Acufex™ interference screws.

The isokinetic tests were performed preoperatively, then three months postoperatively and one year postoperatively. The following parameter were obtained for both flexors and extensors at two speeds (90°/sec and 120°/sec): peak torque, total work and average power. At the preoperative test both injured and contralateral knees were tested, at three months and one year only the involved knee. The figures of the uninvolved knee were used as references to calculate mean deficit / progress percentages for the operated side during the course of the study.

Three patients (number 2, 6 and 14) showed at the preoperative measurements unusually low strength at the 120°/sec tests of the flexors of their uninjured knees. The figures of the uninjured knees had to be used as references in the evaluation of progress / deficits of the injured and operated knees. Therefore all calculated results of those three patients became unrealistically high and did not represent true values. As the mechanical properties of the uninjured knees were otherwise of no interest for this study we decided to exclude these patients from the 120°/sec flexor tests.

Preoperatively the extensors showed a deficit of strength (average of peak torque, total work and average power) at both speeds of 13%. This deficit worsened at three months to 33.7% at 90°/sec and 22.8% at 120°/sec. After one year strength had improved nearly to the preoperative level with a deficit of 2.2% at 90°/sec and 0.14% at 120°/sec.

Flexors: The flexors showed smaller deficits than the extensors. Preoperative figures show deficits of 6.4% at 90°/sec and 3.1% at 120°/sec. At three months the deficit at 90°/sec worsened to 15% but at 120°/sec it improved to the level of the unoperated leg (+0.16%). After one year the strength was at both speeds better than at the unoperated leg (+1.7% at 90°/sec and +4.4% at 120°/sec). The detailed deficit / progress figures for all the measured properties of our study are shown in the tables below.

Table 1 Mean deficit / progress [%]; PT = peak torque, TW = total work, Pow = average power

Table 2 Deficit / progress [%] of strength (average of peak torque, total work, average power)

The strength deficits which resulted from the anterior cruciate ligament defect improved significantly. In both muscle groups and at both test speeds the average strength of the operated knee was after 12 months at about the same level as the uninjured leg. As the flexors are to a lesser extent effected by the operation than the extensors they recovered faster; similar to the findings of Grontvedt et al (8).

The flexors showed at both speeds slightly better results than the uninvolved knee and only the extensors had still a small deficit of 0.147% (120°/sec) and 2.21% (90°/sec) in comparison to the uninjured knee after 12 months.

Further could be shown that apart from flexors at 120°/sec an initial decrease in strength occurred at the three months measurements (as also reported in [6] and [7]).

Grontvedt et al ( 8) still report about 25% weakness of the extensors after six months. In our study already at three months all groups apart from the extensors at 90°/sec (−33.7%) have results better than this (−22.8%, −15.04%, +0.17%). Grontvedt’s study shows 15% deficit after one year and 10% after two years. In comparison to this we could demonstrate nearly normal results (−2.2%, −0.14%, +1.7%, +4.4%) after 12 months. As the test speed influences the results especially during the initial period of decreased strength and Grontvedts study tested at 60 and 240°/sec this might be one reason for the different results.

The overall figures for the patients’ progress are satisfactory. They demonstrate the return of function to an initially unstable cruciate deficient knee.

We would suggest further research into the details of the initial weakness during the first postoperative months as this might have implications for physiotherapy and rehabilitation as well as surgical technique and devices.

Tunnel placement in Anterior Cruciate Ligament (ACL) reconstruction is the single most important variable that a surgeon can control in order to achieve a successful outcome. The femoral tunnel is more critical than the tibial.

Audit tunnel positions after ACL reconstruction in a regional centre.We studied 114 patients undergoing primary isolated ACL reconstruction within a 12-month period. Case notes and radiographs were reviewed retrospectively. Tunnel position was assessed on lateral and AP radiographs of the knee. A review of literature established optimal tunnel position. Measurements of tunnel position were made according to the methods described by Jonsson.

16 surgeons (8 consultants and 8 registrars) performed 57 arthroscopic and 57 open reconstructions, using 24 hamstring and 90 bone-tendon-bone autografts. Femoral tunnel drilling was through the medial arthroscopic portal (24) or the tibial tunnel (90). 85 sets of radiographs were available for review (21 not performed post-operatively, 8 not found)

In the sagittal plane, the femoral tunnel insertion should be within the posterior third along an extended Blumensaat’s line and the tibial tunnel between 41 and 49% along the tibial joint line from anterior to posterior. In the coronal plane, the tibial tunnel should exit between 41% and 49% along the tibial joint line, from medially. Our results showed that 65% of femoral tunnels were outside this position, 23% of the tibial tunnels out in the sagittal plane and 55% out coronally. Of those drilled through the medial portal, only 5% of the femoral tunnels were outside our recommended position.

Clinical Governance demands that guidelines for best practice are established and that audit ensures these standards are met. Anatomical studies give useful data in determining acceptable standards, as demonstrated in our audit. To enable this it is imperative that post-operative radiographic assessment is performed routinely.

Ultra high molecular weight polyethylene (UHMWPE) was introduced into clinical practice by Charnley in November 1962 and has remained the standard material for the hip and other total joint arthroplasties.

Wear of the UHMWPE cup, although studied from the beginning, did not appear to be a clinical problem although Charnley suspected that this would be so in the long term.

A review of the outcome of the Charnley low-friction arthroplasty in patients under the age of 40 years at the time of the operation has shown that the incidence of cup migration was exponentially related to the depth of cup penetration. A prospective study using 22.225 mm alumina ceramic (Al 20 3 ) head articulating with cross linked polyethylene was set up with the initial penetration of 0.2 – 0.4 mm in about 2.5 years with no further penetration. The clinical results mirrored closely the experimental results obtained with the identical set of materials and design. The clinical results have now reached 14 year follow-up and the initial total penetration of 0.2 – 0.4mm has remained unchanged.

Review of long term results of the Charnley LFA has shown a mean penetration rate of 0.1 mm/year (0.02 – 0.6). With a mean penetration rate of 0.1 mm/year, the revision rate for cup wear and loosening in patients under the age of 50 at the time of the LFA, and with a follow-up to 32 years, is in the region of 10%. If the penetration rate remained at 0.02 mm/year or less then no cups have been revised for aseptic loosening. Ceramic / UHMWPE articulation is the next stage of evolution of the Charnley LFA. A prospective study using zirconia 22.225 mm head is approaching 7 year follow-up in over 1000 cases.

We retrospectively analysed three hundred and one infected total hip replacements. Infection was defined on the basis of the surgeons clinical impression. This included a thorough history and physical examination, laboratory and radiographic evaluation. Peri operative findings were also taken into consideration.

Despite the overt appearances of sepsis fifty seven of these three hundred and one cases demonstrated no bacterial growth. These were excluded from the microbiological analysis.

The remaining two hundred and forty four cases oven bacteriological evidence of deep infection. Thirty seven cases grew two different organisms both of which were felt to be clinically significant. The remainder grew a single organism. Hence a total two hundred and eighty one bacteriological isolates were grown.

Coagulase negative staphylococcus accounted for 54.8%, staphylococcus aureus 13.5%, streptococci 8.9%, Escherichia coli 6.1% and diptheroids 2.5%.These organisms were plated out in a standard fashion against a variety of antimicrobial agents.

We analysed ten antibiotics and their sensitivity profiles against the spectrum of organisms demonstrated by this series.

Best antimicrobial coverage by a single antibiotic was afforded by fucidic acid (85.3%) and erythromycin (79.6%). Gentamicin was found to be sensitive to only 76.1% of the bacteria present at the time of revision for deep infection.

Combining gentamicin with other antibiotics improved the theoretical coverage. A combination of gentamicin and fucidic acid demonstrated a 97.5% coverage. Gentamicin with erythromycin gave 95.2%.

When treating the infected arthroplasty it may be beneficial to add extra antibiotics to bone cement. This may either be to the cement spacer in a two stage revision or to the definitive cement in a single stage revision. We would suggest that fucidic acid or erythromycin would be good candidates for this. These candidates should also be considered when designing the next generation of combination antibiotic acrylic bone cements.

Periprosthetic osteolysis has attracted attention as a cause of loosening after arthroplasty. The aim of the present study was to examine inflammatory cell localization and the occurrence of apoptosis in granulation tissue from patients who required revision arthroplasty due to loosening caused by osteolysis.

7 patients were studied comprising 3 patients who underwent FHR and 4 patients who underwent THR. Their mean age at the time of surgery was 63.6 years. The mean period from their previous operation to revision was 8.8 years.

Granulation tissue was collected from around the loosened implant fixed in 4% paraformaldehyde and embedded in paraffin. Sections were cut and were first stained with hematoxylin and eosin. Next, immunohistochemical studies were performed using the avidin-biotin complex method. CD45 was used as the primary antibody to detect T cells, and CD68 was used to detect macrophage-like cells. The activity of the macrophage-like cells was assessed with anti-I-NOS and anti-MMP-9.

Apoptosis was investigated using anti-single-stranded DNA (ssDNA). Using another granulation tissue was stored at −80%C, DNA was extracted, and the presence of DNA fragmentation was detected by agarose gel electrophoresis.

Vascularization and infiltration by a large number of inflammatory cells were seen along with large multinucleated osteoclas-like cells. Immunohistochemical studies revealed CD45-positive cells primarily around the blood vessels. The CD68-positive cells were mainly multinucleated cells. The multinucleated cells were i-NOS-positive in 4 patients, and were MMP-9-positive in 5 patients.

The nuclei of many of the multinucleated cells were positive for ssDNA. Agarose gel electrophoresis of DNA showed a marked ladder pattern at the 170 base pair region. This finding indicated DNA fragmentation or apoptosis.

Apoptotic cells were seen in granulation tissue harvested from around loosened implants suggesting that apoptosis may play a role in the pathophysiology of osteolysis.

Our purpose was to evaluate the incidence of anterior knee pain after ACL reconstruction and the associated affecting factors.

The study assessed 50 ACL reconstructed knees: 29 males and 21 females. The age at surgery was from 14 to 39 years old, with 23.7 years old on the average. The ACL injury was unilateral in all cases, and the normal side was defined as the control. We treated chronic ACL-deficient knees by reconstruction of the ligament through a limited arthrotomy using one-third of the patellar tendon (BTB) with the Kennedy LAD as a graft. Anterior knee pain was classified into 4 group: absent, trace-mild, moderate, and severe. We evaluated the height of the patella, knee extension strength, anterior laxity, leg rotation, Lysholm score, and loss of extension. Anterior laxity and leg rotation were measured by a three-dimensional analyzer.

Ten of the fifty knees (20%) had anterior knee pain. Knee extension strength (reconstructed side/control side) was 71.1% in the cases with anterior knee pain and 84.2% in the cases without anterior knee pain. A significant difference was found between these values. Regarding leg rotation, 4 knees showed normal leg rotation (physiological screw home movement) in the cases with anterior knee pain, compared to 31 knees in the cases without anterior knee pain. There was a significant difference in the incidence of anterior knee pain between the cases with normal leg rotation and the cases without. Other factors failed to show any significant correlation. In this study, knee extension strength and leg rotation had a correlation with anterior knee pain.

This is a retrospective assessment of the performance of a consecutive series of the titanium uncemented Gemini femoral component. The Gemini uncemented stem (De Puy) is a modular titanium femoral stem with a cobalt chrome head. It has proximal porous coating allowing stable fixation by bony in-growth and a smooth distal stem allowing mechanical fixation.

Using a direct lateral approach, 152 consecutive patients underwent a total hip replacement using the Gemini uncemented femoral component and an unce-mented cup. Patients were regularly assessed clinically (Harris hip score) and radiologically (Engh’s criteria for fixation of the prosthesis). Kaplan Meier survivorship analysis was used to assess survival.

16 patients were lost to follow-up and 30 were dead with the THR in situ, leaving 106 hips for final analysis, at a mean follow-up of 106 months. The mean age of the group was 60 years (range 25–83) and OA was the commonest diagnosis. The mean Harris hip score improved from 34 to 92(range 83–100). 7 stems have been revised, four of which for aseptic loosening and a further two are radiologically loose. Mean time to revision was 41 months (range 14–76). By Engh’s criteria, 90% of the hips had stable bony fixation; only 4% of the patients complained of thigh pain at final follow-up. Kaplan Meier survivorship analysis with aseptic loosening as endpoint indicated a survival of 93% at 8 years.

A mid-term result with the Gemini uncemented stems at a mean follow-up of approximately 9 years was excellent. This is in sharp contrast to the cemented stem of similar design, even though the uncemented version was used in younger and more active group of patients. Titanium alloy is biocompatible allowing for excellent bony in growth, making it an ideal alloy in the manufacture of uncemented stems. Having a modulus of elasticity close to that of bone explains the low incidence of thigh pain.

The aim of this study was to review the results of the R. Mathys Isoelastic total hip replacement as for five years in this institution.

For the purposes of this study the patients were invited by letter to attend a review clinic. An examination of the hip was made and hip scores calculated. An up to date radiograph was performed and radiolucent lines assessed in comparison to the initial postoperative radiograph.

78 hips in 64 patients were identified from the records. 5 patients had died before review and 18 hips had been revised. Of the patients who died, none had died in the immediate postoperative period and all the deaths were of unrelated causes.

The revised hips were revised for aseptic loosening in 17 cases and infection in one. The mean time to revision was 53 months. All the loosening was femoral.

In the reviewed patients the mean length of follow up was 101 months.

The mean Harris score was 80.3. The mean Merle d’Aubigne score was 13.6. Significant lucent lines were noted in 2 acetabular components and 22 of 43 femoral components.

Life tables were constructed with both best and worst case scenarios. The end point for failure was taken as revision or the date revision was planned. A further set of life tables were constructed adding radiological signs of failure to the criteria.

Survivorship was, at best, 53% at ten years. If radiological failure is taken into account and lost to follow-up patients are counted as failures, “the worst case scenario”, the rate falls to 18% at ten years. A second important finding was that a large number of the patients were subjectively happy with their hip and had been discharged from clinical follow-up in spite of deteriorating radiographs

We feel that this is a poor implant, which needs ongoing clinical and radiological review, and cannot recommend its further use.

This study constitutes the minimum 5-year follow-up (mean 8.8 years; range 5 – 11.5 years) of a consecutive series of 40 proximal femoral allografts performed for failed total hip arthroplasties using the same technique. Nine of these cases had been two stage reconstructions for the management of infected total hip replacements with bone loss. In all these cases the stem was cemented into both the allograft and the host femur. The host bone was resected in 37 cases, and the greater trochanter reattached with a cable grip in 33 cases and with wire and mesh in 3 cases.

The patients were reviewed by an independent observer. There were 4 early revisions (10%): one for infection, one for non-union of the allograft host junction, and two following revision of a failed acetabular reconstruction. Three further acetabular revisions have since also been performed. Junctional nonunion was seen in 3 cases (8%), two of which were managed successfully with bone grafting and bone grafting and plating respectively. Instability was observed in 6 cases (15%). Trochanteric non-union was seen in 17 cases (42.5%) and trochanteric escape in 10 of these (25%). The mean Harris Hip Score improved from 39 to 79. Severe resorption involving the full thickness of the allograft was seen in 7 cases. This progressed rapidly and silently but has yet to lead to the failure of any of the reconstructions.

Although there was a high early complication rate, the medium term survivorship is excellent, and the clinical outcomes highly satisfactory. The striking observation of severe allograft resorption may be related to a combination of factors. These include the absence of any masking or protective effect that the host bone may have proximally, and surface revascularisation with stress shielding secondary to solid cemented distal fixation. Although continued surveillance is warranted, these results justify the use of structural allografts for selected cases.

This is a retrospective assessment of the performance of the titanium cemented Gemini femoral component. The Gemini stem (DePuy) is a modular titanium femoral stem with a cobalt chrome femoral head. It has a roughened proximal surface finish to enhance cement bonding and a fixed distal centraliser.

205 total hip replacements were performed using a titanium cemented Gemini stem and an uncemented cup. All the operations were performed by a lateral approach using modern cementing technique. Patients were assessed clinically (Harris hip score) and radiologically. Kaplan Meier Survivorship analysis was used to assess survival.

8 patients were lost and 36 patients died with their total hip prosthesis in situ. The average follow-up in the remaining 161 hips was 70 months (range 37–124 months). The average age was 70 years (range 35–91). Osteoarthritis was the commonest diagnosis and majority of the patients was female. Using the Barrack’s criteria for cementing quality, more than 85% of the hips belonged either to grade A or B with an adequate proximal cement mantle. 28 hips have been revised (26 of which for aseptic loosening) and a further ten have been recognized as radiological failures. A small sized stem was used in over 85% of the failures. Mean time to revision was 3.1 years. Survival according to Kaplan-Meier Survivor curves at 6 years was 72%.

There is a high incidence of early failure associated with these cemented titanium stems (28%). The possible mechanism of failure is as follows. The rough surface finish and the flexible titanium alloy are likely to produce large amounts of wear debris and the centraliser which is fixed to the stem probably acts as an area of stress concentration causing accelerated destruction of the distal cement mantle. Based on our experience, the continued use of this cemented stem is no longer justified.

This study was performed in order to review the medium term clinical and radiographic outcome of long stem cemented femoral revisions using second generation cementing technique and identify factors predictive of success or failure.

110 long stem revision hip replacements in 106 patients were performed between 1983–1994. There were 51 males and 55 females of an average age of 69 years with a mean follow up of 6.7 years and a minimum follow-up of five years. Clinical assessment included chart review, and assessment by an independent observer using the Harris Hip Score and the Short Form-36. Radiographic review was performed by two independent observers assessing quality of cementing, loosening, trochanteric union, and heterotopic ossification. The cementing technique was evaluated in both the areas of previous fixation, as well as in the new bone below the tip of the previous stem. We reviewed 93 hips in 90 patients, the remainder having either died or been lost to follow-up. 89% of the patients had improved Harris hip score by more than 20 points. Using the Kaplan-Meier method, fifteen-year survivor-ship was calculated at 92.8%. Three (3.2 %) femoral components were revised, six (6.4%) additional femoral components subsided but were not revised; five of these showed poor cementing technique in the virgin zones beyond the area of the previous stem, and two had cortical perforations. Complications included; 7 (7.5%)dislocations, 6 (6.4%) periprosthetic fractures, 2 (2.2%) infections, and 14 (15%) trochanteric non-unions.

Most reports of femoral revision with cement in revision total hip arthroplasty have shown poor results. However, there are no reports that rely solely on long-stem components. This study shows that long stem cemented femoral revisions have an excellent medium term survivorship, good clinical results and high satisfaction rates. The quality of distal cementing is of great importance, as distal radiolucencies and poor cement technique are predictive of failure.

We report the results of seventy-six Harris Galante Porous Cups (HGP 1) in sixty-three patients treated by Total Hip Arthroplasty (THA) with a diagnosis of avascular necrosis (AVN) of the femur (grade III and IV). The cups were inserted between 1986 and 1994 and followed prospectively. Seventy hips with a follow up of more than five years (mean 7.6 years) were reviewed.

At last review the mean Harris Hip Score was 94 (standard deviation (& dcl001;) .8), preoperatively the mean had been 29 (& dcl001;14.7). Radiographically there was no evidence of acetabular migration. The revision rate of the femoral prosthesis was 8.6%, however only three stems (4.3%) were revised for loosening the rest being revised to allow down sizing of the femoral head. The revision rate for the acetabular prosthesis was 7.1%, (five cups). At the time of revision none of the cups were clinically loose and only required the liner to be changed. The complication rate was low with no deep infections or dislocations and only nine hips, (11.8%) with grade III heterotopic ossification. Survival analysis for both stem and cup at 8 years is 96.3% (confidence interval 91 – 100%), with a worst-case survival of 93.6%, (C.I 87.4 – 99.9%)

Previous studies of patients undergoing cemented THA for the treatment of advanced AVN have reported a high incidence of component loosening. This study shows good medium term results using the Harris Galante Porous cup for acetabular reconstruction with cemented femoral components for the treatment of this difficult problem.

A prospective study of Charnley low friction arthroplasty in patients under the age of 51 at the time of surgery.

1092 patients, 668 women and 424 men, mean age 41 years (12–51) at the time of surgery had 1434 Charnley low-friction arthroplasties carried out between November 1962 and December 1990. At mean follow-up 14.2 years (1 – 32), 742 patients (973 hips) are still attending and patients’ satisfaction with the outcome is 96.2%. Survivorship was 95.24% at 10 years and 58.67% at 27 years.

Patients who had had previous hip surgery had revision rate 24.8% compared with 14.1%. Patients with rheumatoid arthritis had fewer revisions than those with developmental hip dysplasia or primary osteoarthritis. Large 43 mm diameter cup gave lower revisions for aseptic cup loosening as compared with 40mm cup. Presence and preservation of subchondral plate, rim support compared to medialization of the cup, use of acetabular cement pressurizer and the reduced diameter neck (10mm) all made a contribution to reducing the incidence of revisions for aseptic cup loosening. Closing the medullary canal with bone block reduced the incidence of aseptic stem loosening. Use of the brace reamers did not affect the outcome and there appears to have been no advantage with the flanged stem.

The long-term problem was the increasing incidence of revisions for aseptic cup loosening. This was exponentially related to the depth of cup penetration by the head of the femoral component.

The long term clinical results of the Charnley LFA remain excellent even in young patients. Rim support of the cup, preservation of the subchondral bone of the acetabulum, cup flange and pressurising of the acetabular cement all make a significant contribution. Distal closure of the medullary canal and central position of the stem are of benefit, but reaming the medullary canal to cortex must be avoided. The long-term problem has been highlighted again as: wear and cup loosening.

We investigate the hypothesis that normal spinal shape is genetically determined raising the possibility that individuals with scoliosis may inherit an ‘at risk’ spinal shape leading to the clustering of scoliosis within families.

A large scale study of spinal topography (Quantec system) in straight-backed sibling pairs of schoolchildren was undertaken. All children had no family or past history of spinal pathology and passed a modified Adams forward bend test. 223 sibling pairs were scanned including 28 heterozygote and 11 homozygote pairs. Control groups were constructed by breaking the sibling pair and replacing the removed sibling with an age, sex matched, unrelated counterpart. A sagittal spine line was extracted and analysed using principal component analysis to produce four scores accounting for 97.5% of the cumulative variation in shape. The scores were analysed by intraclass correlation coefficients (ICC).

The results for the second score were:-

All sibling groups showed greater correlation of sagittal profile for the second principal component than unrelated controls. Significant correlations in shape were seen for both twin groups where no correlation was seen with controls. A significant correlation was observed in same sex pairings. This work suggests that some elements of spinal profile may be familial but also shows correlation with sex. Both of these observations may be important in the aetiology of idiopathic scoliosis.

We assessed the Japanese specific bone age standard with Tanner-Whitehouse 2 (TW2) method for the evaluation of skeletal maturity in adolescent scoliosis.

TW2 bone age was investigated by the left hand-wrist X-rays of 120 girls with adolescent scoliosis. Their chronological age ranged from 10.2 to 19.0 years. Because Risser’s sign is uncertain between Risser IV and V, for comparison of TW2 bone age with Risser’s sign, we classified apophyses that with an apparent narrowing of cartilage and that with a partial fusion as the later of Risser IV. In addition, clinical courses of the skeletal matured cases (adult bones) in 6 months before investigation were reviewed retrospectively. Even or less than 5 degrees change of Cobb’s angle was evaluated as unchanged. Furthermore, bone age distribution of immature cases was also reviewed for comparision of the unchanged group with the progressive group.

None was evaluated as adult bone in the stage from Risser 0 to III. The rate of adult bone which was shown in Risser IV was 43.5%, but 88.9% was in the later of IV. 95.8% of Risser V was already adult bone. Moreover, 93.1% of adult bone was unchanged in their clinical courses. Remaining 4 cases (6.9%) was progressive, but had not progressed in the following 6 months. Bone ages of the progressive immature group distributed in the range from 11.7 to 13.9 years. Those of the unchanged immature group distributed mainly over 13.1 years.

Although it is necessary to follow the immature longitudinally, adult bone appeared almost in the later of Risser IV, and appeared earlier than Risser V. And Cobb’s angle may become unchanged before adult bone. At least adult bone would be an indicator between Risser IV and V.

Side shift exercise was originally described by Mehta. Since 1986, we adopted it for the treatment of idiopathic scoliosis. Outcome of the side shift exercise for the patients with idiopathic scoliosis after skeletal maturity was evaluated retrospectively. Fifty-three patients with idiopathic scoliosis whose curve was greater than 20 degrees by the Cobb’s method were included in the study. All the patients were treated only by the side shift exercise and their treatment was started after skeletal maturity. Skeletal maturity was diagnosed by Risser’s method as either grade IV or grade V. The study comprised five men and forty-eight women. Twenty-six patients had thoracic curve, eight had thoracolumbar curve, and nineteen had double major curve. Patients were instructed to shift their trunk to the concavity of the curve repetitively while they were standing and to maintain the side shift position while they were sitting. In double major curve, larger curve was the subject of the treatment. The average age at the beginning of the treatment was 16.3 years (range, 13 to 27 years), and the average age at final follow-up was 19.8 years (range, 14 to 33 years). The average follow-up period was 3.5 years (range, one to 11 years). The average Cobb angle at the beginning of the treatment was 33.3 degrees (range, 20 to 74 degrees), and the average Cobb angle at final follow-up was 32.2 degrees (range, 10 to 73 degrees). Curves of four patients decreased 10 degrees or more. Most of long term follow-up studies reported that untreated idiopathic scoliosis progressed even after skeletal maturity. Although the follow-up period was much shorter, results of the present study suggested that the side shift exercise was a useful treatment option for the management of idiopathic scoliosis after skeletal maturity.

Ongoing debate exists as to the integrity of the abdominal musculature unit in maintaining spinal support and stability. It is thought that the intra-abdominal pressure generated is important in spine stabilisation. Congenital aplasia of the abdominal musculature, i.e. prune belly syndrome (PBS), might therefore result in loss of spinal function and stability. We discuss the possible role of an intact abdominal musculature mechanism in maintaining spinal saggital balance and its relevance to low back pain with this case illustration of PBS. We also review the literature for the incidence of spinal deformities related to PBS.

We present a unique case of a 33-year-old male with PBS that resulted in loss of spinal saggital balance and development of a thoracic hypokyphotic deformity and thoracolumbar scoliosis. The patient also suffered from mild low back pain. Literature review suggests that secondary scoliosis appears to be the most commonly reported spinal deformity with up to 36% of cases being affected in one study.

Unequal compressive forces on the vertebral end-plates as a result of changes in static rib support, dynamic paraspinal muscle support, and changes in intrathoracic and intra-abdominal pressures may be the proposed mechanisms for the spinal deformities. Compensatory lumbar paraspinal over-activity due to the inability to generate normal intra-abdominal pressures because of a deficient abdominal wall musculature mechanism seems to be the plausible explanation for the thoracic hypokyphotic deformity observed. As a corollary, a failing abdominal wall musculature mechanism has been implicated in the risk for low back pain and its sequelae. Our case implicates that an intact abdominal musculature unit might be important in the maintenance of overall spinal function and stability. Maintaining normal intra-abdominal pressures, and the effects of abdominal exercises on this mechanism, i.e. training specificity, remain an important adjunct to our routine treatment of patients with low back pain.

We perform arthroscopy of the hip in cases like osteoarthritis, aseptic necrosis of the femoral head, rapidly destructive coxarthrosis to exactly locate the site and extent of the lesion of articular cartilage, acetabulare labrum, and synovial membrane. 381 hips in 279 patients were examined by an arthroscopic technique during the last 16 years. Our technique consists of a three directional approach to the hip joint which facilitates a global view of the joint. This three directional anterior, lateral, and antero-lateral approach means the advantage of the swift replacement of the optical instruments and the easy insertion of arthroscopic tools.

Arthroscopic observation is also very useful for academic purposes. Pathological change of cartilage in osteoarthritis of the hip were classified into 4 grades according to the arthroscopic findings. In 113 joints only biopsies for synovial tissue, cartilage or acetabular limbus were performed. Arthroscopic surgical procedures such as joint debridement for osteoarthritis, synovectomy for rheumatoid arthritis, extraction of loose bodies, release of adhesions between the joint capsule and femoral head, and partial resection of the limbus were also carried out in 60 joints with a mean follow-up of 48 months. Average hip score according to Japanese Orthopedic Association achieved in pain point from 6 points to 24 points. With new improved instruments and three-directional technique, hip arthroscopy is rather easy to perform and less traumatic to the patient therefore we believe that it is suitable procedure for the relief from the coxalgia caused by osteoarthritis, rheumatoid arthritis, and torn limbus.

Endochondral ossification involves a well ordered sequence of cellular events. Chondrocytes change their morphology and functions and are ultimately removed by the process of apoptosis. A variety of apoptotic-related signals have been characterised. These include Fas receptor (FasR)/Fas ligand (FasL), p53 and Bcl family. However, there is little known regarding the activity of these signals in the process of fracture healing. The purpose of this study was to investigate mRNA expression of apoptotic signals using RNase protection assay (RPA) and immunohistochemistry in endochondral bone formation.

BALB/C mice aged 8 to 10 weeks were used for this study. First, a transverse fracture was made in the right tibia. Mice were euthanised at 1, 2 and 3 weeks postfracture. The calluses were harvested and studied for the expression of caspase-8, a key enzyme of apoptosis, and apoptosis inducers: tumour necrosis factor-alpha (TNF-α) and its receptor p55, FasL and Fas receptor (FasR), and TNF-related apoptosis-inducing ligand (TRAIL). Four mice at each timepoint were used for immunostaining of fracture callus. Sections were incubated with primary antibody then labelled by avi-din-biotin complex method. Another four to ten tibiae were used for RPA. Fracture callus were harvested and snap frozen in liquid nitrogen. RNA was isolated by TRI reagent and BCP, and mRNAs expression of apoptotic signals were detected.

At each timepoint, mRNA of caspase-8, TNF-α, p55, FasL,FasR and TRAIL were detected by RPA. Immunostainings clearly showed that those apoptotic-related proteins were expressed by callus chondrocytes. Cartilaginous callus is replaced by woven bone in endochondral ossification. In this process, chondrocytes should be removed by the process of apoptosis in which death factors are elaborated directly in both an autocrine and paracrine manner.

To investigate the underlying mechanism of osteocyte death in osteonecrosis of the femoral head (ONFH).

Although there are a plethora of conditions that predispose to ONFH the underlying mechanism that results in the death of osteocytes is poorly understood. Consequently, treatment for early disease has a variable outcome. Recent investigation has focussed on the role of nitric oxide (NO) in the local control of bone turnover. NO is central to bone cell metabolism and has been implicated in the development of apoptosis.

Bone samples were harvested from the femoral heads of 40 patients undergoing total hip arthroplasty – 20 for advanced ONFH and 20 for osteoarthritis (control group). Immunocytochemical techniques were used to demonstrate evidence of NO synthase (iNOS and eNOS) as a marker of NO production and for evidence of apoptosis.

There was a marked increase in the expression of both eNOS and iNOS in the bone marrow and osteocytes from patients with ONFH secondary to steroids and alcohol with a correspondingly high proportion of apoptotic cells. Very little evidence of either eNOS or iNOS could be demonstrated in the control group and no significant apoptosis could be demonstrated. Samples from patients with ONFH secondary to sickle cell disease likewise had little evidence of apoptosis and a less marked increase iNOS production.

Our findings suggest that sickle cell disease may cause infarction of bone which subsequently leads to osteonecrosis. However, steroids and alcohol, or their metabolites, may have a direct cytotoxic effect upon bone leading to an increased NO production and NO-mediated apoptosis rather than necrosis. Our findings may provide important clues as to the underlying pathway leading osteocyte death. Therapeutic measures aimed at preventing production of toxic levels of NO or by blocking specific pathways in apoptosis may provide effective an treatment during the early stages of ONFH by halting disease progression.

To compare the effectiveness of ALIF, using the Hartshill Horseshoe cage, and Graf ligamentoplasty for stabilisation of comparable severity of degenerative disc disease.

Between 1995 and 1997, 27 patients who had single level ALIF with Hartshill Horseshoe cage [group A], and 28 patients who had single level Graf ligamentoplasty [group B] were assessed by Oswestry disability index, a subjective score, Zung Depression Scale [ZDS], and Modified Somatic Perception Questionnaire [MSPQ]. The two groups were similar in age and sex distribution. The patients were randomized, and procedures were all undertaken primarily for symptoms of back pain, although some patients in each group reported some leg pain. No patients with the ALIF group had any MRI evidence of neurological compromise. Where there was any degeneration at more than 1 level, discography was undertaken (8 patients in each group) confirming an isolated pain source at a single level. The duration of back symptoms and leg symptoms in the two groups was similar. There was some difference in the distribution of the MRI grade of disc degeneration between the 2 groups, but this did not reach statistical significance. Following is the characteristic of the 2 groups:

In this group, Graf ligamentoplasty procedure had a statistically significant better outcome than ALIF with the Hartshill horseshoe cage.

This may be due to the retention of some degree of normal mobility of the affected segments after stabilisation with Graf ligaments. However, at a minimum follow-up of 2 years, these represent only medium term results. There is a potential for a change in the outcome in the long term.

To determine whether systemic nitric oxide production in tourniquet-induced skeletal muscle ischaemia-reper-fusion injury (SMRI) is dependent on release of vascular endothelial growth factor (VEGF), a modulator of nitric oxide cytoprotection in myocardial ischaemia-reperfusion injury.

Mice were randomised (n=10 per group) into: time controls (no tourniquet) and test animals (bilateral hindlimb tourniquet ischaemia). Blood samples were collected in test animals prior to ischaemia and after reper-fusion. In controls, blood samples were collected at the same corresponding time points. Serum VEGF, nitric oxide metabolites (nitrite and nitrate) and the proinflammatory cytokine tumour necrosis factor (TNF)-α (an indicator of systemic inflammation) were determined. At the end of reperfusion, the lungs and muscle (right gastrocnemius) were harvested and tissue injury determined by measuring myeloperoxidase (MPO) activity, a marker of neutrophil infiltration. Data are presented as mean ± SEM and statistical comparison was performed using one-way analysis of variance (ANOVA) with significance attributed to P < 0.05.

In comparison to control animals, muscle (4.9±0.3 versus 4±0.03 units/g of wet tissue; P=0.02) and lung (16.7±1.9 versus 10.4±0.5; P=0.005) MPO activity at the end of repercussion was significantly greater in test animals. The table shows the results with respect to serum cytokine levels and nitricxide metabolites.

These data demonstrate that SMRI results in local and systemic proinflammatory responses. In contrast to myocardial ischaemia-reperfusion injury, nitric oxide production in tourniquet-induced SMRI is VEGF-independent. Alternative mechanisms for nitric oxide production in tourniquet-controlled extremity surgery requires further evaluation.

The most considerable cause of nerve root damage are compression force and stretch force. Many researchers had reported about experimental study of the compression force, but it is difficult to find the report describing the stretch force to the nerve roots. The purpose of this study is to evaluate the physiological reaction of nerve roots of rats nuder stretch force.

The nerve roots were prepared from the cauda equina of 8 Wister rats (weight: 300 – 400g). We investigated the changes in threshold and action potential of the nerve roots under stretch force and compression force.

The threshold of the nerve roots increased and action potential decreased in parallel with stretch force. Also, the threshold and action potential recovered after releasing the stretch force. On the other hand, by compression force, the action potential decreased parallel with compression force, but the threshold did not change with compression force. Ten minutes after releasing compression force, the action potential did not recover as much as before, and the threshold increased rather than control.

The different physiological reactions that occurred between compression force and stretch force are hard to explain by circulation insufficiency, as previously reported (hypoxemia and lack of nutrition). We considered that the etiology of the stretch force might be a change in internal pressure of nerve roots and a structural change in nerve cells.

The physiological reaction of the nerve root under stretch force differed from that under compression force and recovered from the damage after release from stretch force.

Disuse atrophy is the basis for profound physiological changes of the muscles of immobilised limbs. The aim of this study was to use ultrasound to assess the quadriceps musculature and to try and measure atrophy. We monitored the effects of enforced reduction of mobility due to trauma on the intramuscular architecture of the quadriceps using high resolution real-time ultrasonography (HRRTU) in 13 skeletally mature male patients (43.2 years, range 16 to 82 years), with an isolated unilateral diaphyseal fracture of the femur or of the tibia. All patients had undergone interlocked intramedullary nailing (IIN). Using HRRTU, the pennation angles and muscle fibre lengths of vastus lateralis, the cross sectional area (CSA) of the rectus femoris, and the quadriceps muscle layer thickness (MLT) were measured in the injured and the normal contralateral limb. Repeated measurements showed the technique of measurement of the variables used in this study to be highly reproducible. There was a significant difference in the angle of pennation of the vastus lateralis in the nailed (15.4°) and the unnailed limb (21.2°), documenting that muscle atrophy causes a change to muscle architecture that results in a significant decrease in pennation angle (p = 0.0002). The muscle fibre length was significantly different (p=0.002) and there was a significant correlation between pennation angle and muscle fibre length (r=−0.51, p=0.001). There was also a significant difference in the quadriceps MLT (p=0.001) and CSA of the rectus femoris (p=0.0004) implying that the whole of the quadriceps muscle is affected.

We hypothesise that the stiffness of the acetabular component influences the stresses transmitted to bone. Thus stress shielding or stress overload of the underlying host bone may be influenced by the choice of fixation method. In addition, we believe that the so called “brake drum effect” plays a significant role in the development of rim stresses and subsequent failure of fixation.

We have constructed a jig which allows the direct comparison, under controlled conditions, of contact stresses measured behind the acetabular component of polyethylene controls, uncemented metal backe cups and cemented all polyethylene cups, under physiological load. The design of the jig also allows measurement of stresses transmitted to the acetabular rim of the same three prostheses in order to confirm the presence and magnitude of the brake drum effect. The contact stresses are measured by miniature pressure transducers which are inserted through specially drilled holes in the shell of the jig so that the transducer is flush with the prosthesis under test. A total of 6 transducers are arranged in concentric circles radiating away from the prosthetic dome, so that contact stresses may be directly measured in various parts of the acetabular bed under conditions that reproduce as closely as possible the situation in a total hip prosthesis in vivo. Thus our method can be compared to other laboratory and theorectical techniques for investigation into stress transmission around acetabular components. The transducers were callibrated prior to each test to ensure parity of test results. The transducers were prestressed to ensure contact prior to each test. 6 polyethylene uncemented liners were tested alone in the jig to act as a control. In the same fashion, the same 6 polyethylene components were tested firstly in an uncemented, metal back acetabular component, and then as a cemented, all polyethylene component.

The results indicate that significantly less stress is transmitted to bone when metal back components are used as compared to cemented components and controls. The data confirms that the brake drum effect occurs in both cemented and uncemented prostheses, leading to at least the absence of compressive forces at the prosthetic rim and in some circumstances tensile forces.

The objective of this study was to compare the wear mode of 100 Mrad PE cups run in a hip simulator to retrieved 100 Mrad PE cups, and to evaluate the efficacy of the PE wear model.

15 In-vitro PE cups: 3 each 0,2.5.50,100 and 150 Mrad (9 channel hip simulator, 6.2 million cycle duration, physiological load profile by Paul, 2000N maximum load at 1Hz using 30% bovine serum). 5 Retrieved PE cups: three SOM cups (Mizuho Medical Instrument Co., COP alloy 28 mm head)-0 Mrad after 8 years of clinical use, two 100 Mrad cups after 15 years of clinical use, two T28 PE 2.5 Mrad cups (Zimmer): 18 years and 13 years of clinical use. The cups were examined using a SEM (Philip XL30 FEG) for wear scar locations and PE wear-topography.

Original machine marks were observed in the weight-bearing areas of the highly cross-linked in-vitro PE. No machine marks were observed for the 0 and 2.5 Mrad in-vitro cups and none were seen in any of the retrieved cups. The formation of more nodules and fibrils in the 0Mrad cups compared to the extensivley cross-linked cups (in-vitro and retrieved) was striking. The frequency of occurrence and length of the fibrils and nodules was dependent on the dose of gamma irradiation. More ripples were formed in the 2.5 Mrad and higher cups compared to the non-irradiated cups (in-vitro and retrieved). The in-vitro cups formed more ripples than the retrieved cups. In general, the SEM features for in-vitro Mrad cups appeared similar to those of the retrieved Mrad cups.

The in-vitro Mrad cups accurately reflected the conditions of the artificial joint in living body. Therefore, comparisons of retrieved PE cups with simulator PE cups appeared to be a very powerful research tool.

(2) SEM observation demonstrated far less wear damage in the extensively cross-linked cups than in the non-extensively cross-linked PE. Thus the extensive cross-linked PE cups appeared to be a significant improvement over conventional PE cups in terms of wear resistance.

Many pathological disease processes are manifested by abnormalities in cellular signalling caused by altered protein expression. Our aims, therefore, were to determine whether ‘’degenerative disc disease’’ results in 1) altered proteome expression and 2) such changes might be used as a marker for the disease process.

Using gel electrophoresis, we analysed the proteome expression of nucleus pulposus (NP) derived from patients with scoliosis (‘normal’) compared to degenerate samples from patients with 1) back pain undergoing spinal fusion (DDD) and 2) sciatica undergoing discectomy (herniated nucleus pulposus or HNP). Normal NP tissue was also obtained from organ donor patients with no previous history of back pain. All samples were investigated in duplicate. Protein concentrations were measured qualitatively by visual analysis in a blinded manner and categorised into high, medium, low or absent. The Kruskal-Wallis analysis of variance was sued to analyse the data. Subsequent proteins of interest were determined on N-terminal protein sequencing.

15 samples each were collected each from scoliosis, DDD, and HNP, but only 4 samples from the organ donor groups. One major protein band difference was observed whose molecular weight was 15 kDa and N-terminal sequence homologous with lysozyme C (lysozyme-C-like-protein - LCLP). DDD and HNP samples exhibited significantly reduced levels of LCLP compared to scoliosis (P< 0.0001). All NP from donor patients exhibited high levels of LCLP, but numbers were too small for statistical analysis. No statistical correlation existed between age and LCLP levels.

The true physiological roles of Lysozyme C remains unclear, but it is a known ubiquitous secretory and hydrolytic protein found in saliva, milk, cerebrospinal fluid and synovial liquid, and thought to function in primary immunity. LCLP loss in degenerate disc tissue might be due to 1) lack of production, 2) increased breakdown through a specific ubiquitin-linked pathway, or 3) polymerisation with tissue-specific amyloid deposition. The inflammatory effects within the NP related to localised LCLP-amyloid deposition offers a plausible hypothesis for patho-physiology of disc degeneration and discogenic pain. Until we determine the true nature and function of LCLP, we are no further in understanding the patho-mechanisms of disc degeneration. Moreover, LCLP loss in the NP of degenerate discs may provide a potential diagnostic marker for degenerative disc disease.

The purpose of this study was to investigate the possible relationship between matrix metalloproteinase-3 (MMP-3) promoter 5A/6A polymorphism and intervertebral disc (IVD) degeneration in the older generation.

One of the important steps in IVD degeneration is disc matrix degradation by matrix degrading enzymes such as MMPs. MMP-3 is one of the potent proteoglycan degrading enzymes and has been suggested to play an important role in IVD degradation. A common 5A/6A polymorphism in the promoter region of the human MMP-3 gene has been identified. This polymorphism was reported to be involved in the regulation of MMP-3 gene expression (the 5A allele has 2-fold higher promoter activity than 6A). We now hypothesize that IVD degeneration is associated with MMP-3 promoter 5A/6A polymorphism.

Forty-nine elderly Japanese volunteers (mean age 74.3 years, range 64–94 years) were studied. Each lumbar disc was graded according to the radiographic classification system of IVD degeneration described by Kellgren and Lawrence. The 5A/6A polymorphism was determined with both single strand conformation polymorphism (SSCP) and polymerase chain reaction with allele-specific primers (AS-PCR).

Two subjects (4%) with 5A5A genotype, 16 (33%) with 5A6A, and 31 (63%) with 6A6A were observed. Genotype was totally independent of age and sex. There was a significantly larger number of IVDs graded 2 and higher in the 5A/5A+5A/6A than in the 6A/6A (p< 0.05). The degenerative scores of lumber discs were also distributed more highly in the 5A/5A+5A/6A than in the 6A/6A (p=0.0029).

Many environmental factors have been reported to accelerate IVD degeneration. Recently, genetic factors have also been highlighted as possible risk factors. The 5A allele of the human MMP-3 promoter is a possible risk factor for acceleration of IVD degeneration in people aged over 64 years old. We conclude that MMP-3 plays a key role in the degeneration of IVD in the older generation.

Ulnar drift is a common deformity in the hands of patients with rheumatoid arthritis. There is little in the literature regarding the value of crossed intrinsic transfer with MCPJ arthroplasty (Hellum 1968, Stothard et al 1991). In addition the significance of recurrent ulnar drift on hand function is unknown. The aim of this study is to assess if the addition of crossed intrinsic transfer to metacarpophalangeal arthroplasty has an effect on the recurrence of ulnar drift and to overall hand function.

This is a retrospective comparative study. 73 hands in patients with rheumatoid arthritis undergoing primary 2nd to 5th metacarpophalangeal joint (MCPJ) replacements were studied. In 28 hands a crossed intrinsic transfer was performed and in 45 hands it was not . A similar splintage and rehabilitation programme was followed in each group. Mean follow up was 50 months.

Ulnar drift and active range range of motion, Sequential Occupational Dexterity Assessment (SODA) functional score, patient satisfaction , grip strength.

The two groups had similar preoperative ulnar drift (crossed intrinsic transfer group mean 27 degrees, comparative group 29 degrees, p=0.44). At follow up the crossed intrinsic transfer group had statistically less ulnar drift (crossed intrinsic transfer group mean 6 degrees, comparative group 14 degrees, p=0.01). There was no difference at follow up in active flexion, extensor lag, SODA score, grip strength and patient satisfaction (both groups had 70% improved function).

Dupuytren’s contracture (DC) is a non-lethal disabling disease, characterised by a progressive fibrosis of the deep palmar fascia, produced by an increased deposition of collagen within the extracellular matrix (ecm). Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that degrade ecm proteins. Their activity is regulated by growth factors, cytokines and by specific tissue inhibitors (TIMPs). An imbalance in the normal relationship between expression of MMPs and TIMPs is believed to contribute to the pathogenesis of other fibroproliferative diseases.

We have performed a detailed immunohistochemical analysis of DC tissue which provides the most comprehensive profile to date of the MMP and TIMP expression in DC. Sections were immunostained using antibodies against a panel of MMPs and TIMPs. Normal palmar fascia from patients undergoing carpal tunnel release or from cadaveric hands was used as controls.

There was a marked increase in the expression of MMPs and TIMPs within the different areas of DC tissue compared with controls. Both MMPs and TIMPs were expressed in an angiocentric pattern within areas of hypercellularity (corresponding to the proliferative stages of nodules). In some hypercellular areas expression of TIMP1 and TIMP2 exceeded that for the MMPs. Hypocellular cords, which were predominantly composed of collagen, were weakly immunopositive for MMP-2 and MMP-9, but were immunonegative for TIMPs.

Areas of MMP-1 and MMP-2 expression were more intense in the stroma surrounding nodules, and also within the “invading” DC tissue at the dermo-epidermal junction (DEJ) of the skin. Here expression of MMPs was observed around abnormally high numbers of small blood vessels, beneath the rete ridges of the epidermal layer, and also within foci of inflamation.TIMP1 and TIMP-2 were not expressed within the DEJ. These changes were most marked where clinically there was obvious ‘skin pit’ involvement.

Currently the only treatment for DC is surgical. Alternative non-surgical therapeutic protocols might involve manipulating the fibrotic process pharmacologically, for example by seeking to regulate expression of MMPs and their inhibitors.

Fractures about the radial or ulnar aspects of the base of the proximal phalanx or the metacarpal head represent collateral ligament avulsion injuries. Unlike such injuries in the metacarpophalangeal joint of the thumb these injuries are rare and have received scant attention in the literature.

The results of open reduction and internal fixation, highlighting the surgical approach and technique, of collateral ligament avulsion fractures about the metacar-pophalangeal joints of the fingers are presented.

Over a five year period sixteen patients presented to the hand injury service with the above injury. Thirteen of these fractures occurred at the base of the proximal phalanx. Fourteen were acute injuries and two non-unions. These fractures affected a predominantly young population (average age 24 years) and the majority were sustained during sporting activities. All were treated by ORIF except for one in which the patient declined operative treatment. Metacarpal head fractures are assessed through a standard dorsal approach but as the collateral ligament inserts into the volar - lateral aspect of the proximal phalangeal base access to this fracture is best achieved via a volar approach to the digit. Fractures were stabilized with a single interfragmentary screw.

Surgical fixation gave satisfactory results in fourteen cases. All these patients had a full range of finger movement within 3 weeks. One patient developed symptoms suggestive of RSD. At 3 months review all fractures treated by ORIF had united. The patient who declined surgical treatment developed a symptomatic non-union.

Conservative treatment of these unstable fractures leads to non-union. The surgical anatomy dictates the surgical approach, with fractures at the proximal phalangeal base best accessed via a volar approach. ORIF restores joint surface congruity, establishes union and provides stable fixation to allow early mobilisation and return to normal activities.

Restoration of hand function following division of a flexor tendon remains a significant challenge.

We describe a new method of tendon repair. The first suture is placed in the standard fashion, the second suture is inserted with a round bodied needle to avoid damage to the first repair. This is placed at right angles to the first repair and enters the tendon at the furthest point from the cut tendon end. This suture is then tied with the knot on the surface of the tendon, using 4/0 Ti.cron. The repair is completed with a circumferential continuous epitenon suture, using 6/0 Prolene. This method produces a repair with a four-strand core suture and is referred to throughout this paper as the Evans repair.

Flexor digitorum profundus tendons harvested from pigs were used as the experimental model. They were divided at the mid-point and then repaired using either a ‘modified Kessler’ 4/0 Ethibond core suture, a ‘modified Kessler’ 4/0 Ti.cron core suture or the Evans double core suture. The specimens were then tested to failure on an Instron materials testing machine. This produced a figure for the ultimate tensile strength of each repair.

The average tensile strength for the Ethibond Kessler repair was 33 (range, 27–36) Newtons and that of the Ti.cron Kessler repair was 31 (range 21–43) Newtons. The average tensile strength for the Evans repair was 52 (range 43–60) Newtons, and it is significantly stronger than the two standard Kessler repairs (p< 0.001, Student’s t-test). Even the weakest of the Evans repairs was as strong as the strongest of the standard Kessler repairs.

A randomised controlled trial involving 24 patients ( 32 wrists ), 18 wrists being allocated to the single incision group ( S ) and 14 to the double incision group ( D ), was carried out between 1996 and 1999, after clinical evaluation and complimentary EMG studies. Randomisation was performed by one of the orthopaedic secretaries using an envelope technique on the morning of admission. Mean ages were 49.6 ( 32 to 69 ) and 45.8 ( 30 to 54 ) in the S and D groups respectively. The male to female ratios were 2/12 and 5/7 respectively. The pre- and post-operative mass grip strength was measured by a Jamar dynanometer and assessment of post-operative parameters included pillar pain, scar sensitivity, nerve compression symptoms and return to work.

Pillar pain was significantly less in Group D ( Chi-squared = 8.22; P = 0.004 ).

Return to work was less in Group D ( average = 2.6 weeks ( 1 to 12 weeks )) cf. to Group S ( average = 5.6 weeks ( 2 to 16 weeks ) ). ( Wilcoxon Rank Sum Test P = 0.0004 ). No differences occurred in post-operative clinical symptoms ( P > 0.05 ), scar sensitivity ( Chi-squared = 1.025 ; P = 0.506 ) or mass grip strength ( P= 0.506 ).

The tourniquet time was longer for the double incision technique ( average = 15.3 minutes ( 12 to 18 minutes )) cf. to the single incision technique ( average = 12.2 minutes ( average = 10 to 18 minutes )).

The double incision technique is a safe and easy technique for uncomplicated carpal tunnel syndrome resulting in a significant reduction in pillar pain and a more rapid return to work.

The fingertips are important for not only the function of the hand but also cosmetic reasons. In distal phalanx, arteries especially in zone …Ÿ are less than 0.5 mm in diameter however they can be anastomosed ultramicro-surgically with 11-0 suture.

From 1976 to 1999, I have replanted 463 digits in 337 male and 126 female patients whose ages ranged from 4 months to 80 years, with an average of 32.7 years. There were 312 digits with complete amputation, 151 digits of incomplete amputation, 277 digits with trauma in zone …Ÿ and 186 digits in zone … in which more than six months had passed since the replantation.

The results in zone … amputations was better then in cases of amputations in zone …Ÿ because anastomoses of arteries and viens are more relibale in zone … amputation.

I analyzed the results of zone …Ÿ amputation according to types of injury. The survival rate was 100% in clean-cut amputation, 91.7% in blunt-cut, 66.1% in crush and 67.5% in avulsion. So in cases of crush or avulsion amputation in zone …Ÿ, there is relative indication for replantation.

As for postoperative functional recovery, 95% of the survival fingers are in good daily use, or in some use. Compared with stump plasty, our results of survival fingers are far superior functionally and cosmetically. From a survival rate and functinal point of view, replnatation is definitely indicated in cases of zone …Ÿ amputations by clean-cut or blunt-cut and zone … amputations if technically possible.

The purpose of this study is to introduce our technique of free hand screw insertion for scaphoid fractures and clarify the indications of this procedure.

From 1988 to date, we performed this method in 86 cases (75 males and 11 females). Ages ranged from 11 to 73 years (av.: 29). There were 24 cases of acute stable type, 46 of acute unstable and 16 of delayed fibrous union. Screws used were original Herbert screws in 48, other cannulated type screws in 38.

Using an image intensifier, from a small skin incision over the scaphotrapezium joint, a Kirschner wire is inserted to stabilize the fracture temporarily. The wire is pulled volarward to rotate the scaphoid and a second wire is inserted along the intended line of the screw. With the original Herbert screw, after removing the wire, the screw is inserted free-hand. With the other cannulated screws, the second wire is used as guide pin.

Results of 82 cases with follow-up times over 6 months were reviewed. In one case, bony fusion was achieved but revealed symptomatic malunion. In two cases, bony fusion was not achieved. In one of them, an additional bone graft was performed, and good bony union was achieved. In the remaining 79 cases, good bony fusion and good clinical results were achieved.

The best indication for this method is an acute unstable fracture. For acute stable fractures, we recommend this method for three types of patients: those who cannot accept long term immobilization, those who desire to return to athletic activities as soon as possible, and those who also have another fracture in the forearm. It can also be used in cases of delayed fibrous union when good alignment can be achieved and a bone graft is unnecessary.

The use of musculo-skeletal MRI is increasing at spectacular rate, however there have been few rigorous evaluations of its’ clinical effectiveness. This study was conducted to assess the impact of MRI of the wrist on clinical diagnosis and patient management.

A controlled observational study was performed, in which referring clinicians completed questionnaires on diagnosis and intended management before and after wrist MRI. We analysed 118 consecutive patients referred for MRI of the wrist, to the magnetic resonance imaging units at a regional teaching hospital and a large district general hospital. We assessed: changes in clinicians’ leading and subsidiary diagnoses after MRI; their certainty of these diagnoses; and changes in intended patient management.

Five patients had incorrectly completed requests, ten cancelled their appointments and two could not tolerate the MR examination. Complete follow up data is available for 98/101 patients with correctly completed request forms who were examined. The clinical diagnosis changed in 55 of 98 patients (56%). Diagnostic certainty increased in 23 of the remaining 43 patients (53%). Clinicians reported that MRI had substantially improved their understanding of the patients’ disease in 67/98 (68%) patients. There was a change in management in 46/98 (47%) patients, with a shift away from operative treatment. 28 out of 98 (29%) patients were discharged without further investigation. MRI was similarly effective in a regional teaching centre and a district general hospital.

Magnetic resonance imaging of the wrist influences clinicians’ diagnoses and management plans. These results demonstrate the clinical effectiveness of MRI of the wrist in both a regional teaching centre and a district general hospital.

The U-shaped sacral fracture is a fracture pattern poorly recognized, that is not included in the standard classification of sacral fractures. These fractures are significant as they represent spino-pelvic dissociation, have a high incidence of neurological complications and information regarding modern treatment options is sparse. A number of authors have reported isolated cases or small series of patients with this type of fracture, although none explicitly note the bilateral vertical element that makes them U-shaped and represents spino-pelvic dissociation.

We present four patients with U-shaped sacral fractures. All patients were polytraumatised patients of whom three had jumped from a height in suicide attempts illustrating the high energy required to produce this fracture.

Three patients had ilio-sacral screw fixation, supplemented in one with instrumentation from the lumbar spine to the iliac crest. The other had sacral laminectomy with bony stabilization by instrumentation from the lumbar spine to the iliac crest without ilio-sacral screw fixation.

No complications were encountered as a result of fixation. The fixation devices used essentially represent the local expertise that is available. The ilio-sacral screw technique is minimally invasive and appears to provide satisfactory fixation in our limited experience. However as fracture deformity often involves rotation of the upper sacrum, the use of a single screw may not provide adequate support against the deforming forces or allow reduction of the fracture. Additional ilio-sacral screws will provide some rotational control of the sacral fragment if their safe insertion is possible, if not then the forces should probably be neutralized by an additional device from L5 to the pelvis.

The role of sacral decompression is unclear but may be appropriate in the presence of neurological deficit and a severely compromised sacral canal.

These are complex, rare injuries. We recommend their referral to a specialized pelvis/spinal unit for definitive management.

We review the results of the Gamma nail fixation to elucidate its effectiveness in the treatment of peritro-chanteric and subtrochanteric fractures of the neck of femur.

We report the result of 718 cases of Gamma nail fixation in all such cases presenting at our institution since 1988. 573 cases of peritrochanteric and 145 cases of sub-trochanteric fractures were treated by means of standard and long Gamma nail. Age groups of the patients are from 33 to 99 years. No distal locking screw was used in cases of standard nails. All grades of surgeons were involved. Full weight bearing was allowed on the first post operative day. Cases were followed up for one year.

No intraoperative iatrogenic fracture was encountered. Minimal post operative pain was experienced and mobility was regained early. All fractures healed satisfactorily except the following: 51 cases developed coxa vera deformity; 37 cases of undisplaced fractures of base of greater trochanter were noticed at 6 weeks follow up - all healed spontaneously; 1 case of external rotational deformity occurred in a long nail where no distal locking screw was used. 2 cases of deep infection were treated successfully by removal of nail and antibiotic treatment; 4 cases of fracture at the level of the distal end of the prosthesis, presented at 6 weeks to 2 year period following a subsequent trauma, were treated with exchange of device with long nail. Upward penetration of hip screw 22. No case of metal failure observed.

Gamma nail provides a stable fixation in both simple and complex fractures of proximal femur with a much less invasive tehcnique which allows minimal disturbance of fracture haematoma, less incidence of wound infection and less amount of postoperative pain. Early mobility is regained with immediate and unrestricted weight bearing. Biomechanically also Gamma nail produces a better means of osteosynthesis.

The benefits and risks of early fixation of scaphoid fractures were investigated in 88 patients in the working age group with clear bicortical fractures. Patients were randomised using a random number sheet into 44 who had early internal fixation using a Herbert Screw without a cast and 44 who were treated conservatively in a Colles’ type plaster cast for eight weeks. Patients were reviewed at 2,8,12,26 and 52 weeks with pain severity, tenderness, swelling, wrist movement, grip strength, the Patient Evaluation Measure (PEM) outcome score and x-rays assessed at each visit.

There was no difference between groups for age, sex, nature of injury, dominance, side injured or type of scaphoid fracture. The two groups were similar for pain severity at each of the intervals. Eight of the conservative group and one fracture in the operated group did not unite (p=0.01).

At the 8th and 12th week visits the operated group was better than those treated in a cast for wrist range, grip strength and PEM score (less is better). Thereafter there was no difference between groups.

Patients operated on returned to work at a mean of 6 weeks after their injury compared to 11 weeks for those treated conservatively. There were no serious complications, 6 patients had hypertrophic or itchy scars and one had hypoaesthesia in the palmar cutaneous branch of the median nerve distribution.

Early fixation of scaphoid fractures can be offered as an alternative to cast immobilisation with good early benefits and low risk, however the surgery can be technically difficult.

The aim of the present investigation is to study the status of the blood-nerve barrier in the carpal tunnel syndrome and cubital tunnel syndrome using gadolinium enhanced MRI.

The subjects were 68 patients (92 hands) with idiopathic carpal tunnel syndrome and 21 patients (23 elbows) with cubital tunnel syndrome.

The MRI equipment used was a 0.3-T permanent magnet. Using the SE method, T1-weighted axial images were obtained. Then, we intravenously injected gadolinium for enhanced images. We studied the relationship between nerve enhancement and the symptoms of the patients.

Out of 92 hands with carpal tunnel syndrome, 74 hands (80%) showed enhancement of the median nerve. The patients had 58 hands classified as Grade I (sensory disturbance only) out of which 44 hands (76%) showed nerve enhancement , as did 25 out of 29 hands (86%) classified as Grade II (I + thenar muscle atrophy) and all 5 hands (100%) classified as Grade III (II + disturbance of opposition). Enhancement was more prominent in the patients with thenar muscle atrophy. All 23 elbows with cubital tunnel syndrome revealed enhancement of the ulnar nerve. Two elbows were categorized as grade I (sensory disturbance only), 12 as grade II (I + 1’st inter-osseus muscle atrophy), and 9 as grade III (II + claw finger deformity)

In general, capillaries exist inside the endoneurial spaces of peripheral nerves. Intraneural homeostasis is maintained by the perineurium as a diffusion barrier and by the blood-nerve barrier existing in the endothelium. MRI could demonstrate intraneural enhancement at the site of nerve entrapment where intraneural edema resulted from an increase in the vascular permeability of the endoneurium. We conclude that gadolinium-enhanced MR imaging can detect morphological and functional changes of peripheral nerve in patients with entrapment neuropathy.

Concomitant ipsilateral femoral and tibial fractures result from high velocity injuries and are often associated with other, life threatening, injuries. They are rare injuries in children with few published series, none of which comment on the use of flexible intramedullary nails in the treatment of such injuries.

We present our experience of concomitant ipsilateral femoral and tibial fractures in children and discuss the use of flexible intramedullary nails in their management.

Hospital records and radiographs of 19 such injuries in 18 patients were studied. These cases were divided into three groups based on the method of treatment. Group A: (8 cases) both the femoral and tibial fractures were internally fixed.

Group B: (4 cases) only one out of the two fractures had internal fixation while the other was externally immobilised.

Group C: (7 cases) both femoral and tibial fractures were treated with external immobilisation like external fixators, plaster cast or traction.

Six cases in group A were treated with flexible intra-medullary nailing The mean age was 8.5 years. The average follow up was 3.5 years. All patients were reviewed and assessed clinically following discharge from hospital.

Patients treated with internal fixation of both fractures had a shorter hospital stay and were able to weight bear earlier. Limb length discrepancy was common in conservatively treated patients. Mean limb length discrepancy was 3.8 cm of shortening. A better range of knee movement was observed in patients treated with flexible nail for femoral and tibial fracture. Over all a good result was achieved in 70% of the patients. Using our assessment criteria we found that Group A faired better than the other two groups on all accounts.

Only a few small series of such a rare injury has been mention in the literature. More complications have been reported in children under 10 years of age. In our study we found better results when both tibial and femoral fractures were treated with internal fixation. The out come results in our patients were not related to age.

We found that internal fixation with closed flexible intramedullary nailing of both femoral and tibial fractures was a safe and effective technique and has therefore been recommended.

The purpose of this study is to introduce our treatment by skeletal traction in brace and to report the safety and easiness of this method and low incidence of cubitus varus.

In 1980 we developed a specially designed brace for treating the supracondylar fracture, along with a technique of spontaneous reduction by skeletal traction to develop an easy and safe treatment. The brace is made of plastics and aluminum alloy that are radiolucent. The humeral slide bar with attached axillary pad can be moved up and down to adjust the height of the upper arm for each patient.

From 1980 to 1999 we have treated 190 children with displaced supracondylar fracture of the humerus. Their ages ranged from 2 to 14 years old and average of age was 7 years old. The fractures occurred most frequently between the ages of 5 to 6. More boys than girls were injured and the left elbow were more often than the right. Among 190 cases, severely displaced cases were most common. (64%) and moderate case 20%, mild case 16%. The period of follow up was 6 months to 11 years, mean 4 years.

Placing the arm in the brace with the elbow flexed at right angle, unstable fracture site will be stabilized first. Skeletal traction is performed by a spring through the winged screw. The traction is maintained for three to four weeks. Spontaneous reduction of the displaced fragment can be expected and we emphasize that any manipulative technique is not performed during the treatment at all.

Among 190 patients, cubitus varus occurred in only 3 (1.6%) cases because of technical failure. All patients except one obtained excellent functional results, one had 25 degrees of limitation of the elbow flexion. There were no vascular problems or Volkmann’s contracture and ectopic ossification. The results were satisfactory.

Our treatment utilizing the brace and skeletal traction for supracondylar fracture of the humerus in children is safe and effective in preventing cubitus varus.

Much interest and controversy have arisen regarding treatment and prognosis of unstable pelvic fractures. The choice of treatment should be based to a large extent on the long-term outcome. Residual vertical displacement and sacroiliac joint involvement are often cited as being related to poor outcome. This study attempts to clarify whether residual vertical displacement or location of posterior pelvic ring injury correlate with functional outcomes.

33 patients with unstable pelvic fractures not involving the acetabulum were reviewed with greater than 18 months of follow-up. Iowa pelvic scores and descriptive information about sequelae were administered. Fractures were classified according to Tile as 27 type B, and 6 type C fractures. 9 cases were treated with external fixation and 5 cases were treated open reduction and internal fixation. The amount of residual vertical displacement was measured on plain AP radiographs and graded as 0–4,4–10,10–20, or > 20mm. Location of posterior pelvic ring injury was divided into 3 groups, sacral fractures, sacroiliac fracture dislocations, and transiliac fractures.

Residual vertical displacement correlated with the incidence of LBP to some extent, but the difference was not statistically significant. Location of the posterior pelvic injury correlated with the incidence of neurologic injury and gait disturbance.

There was high incidence of lower extremity fractures associated with the pelvic fractures. The incidence of gait disturbance and Iowa pelvic score were not valid as functional assessment tool.

Residual vertical displacement and location of posterior pelvic injury correlated with the functional outcome to some extent.

A prospective randomised study was undertaken of patients with displaced Colles’ type distal radial fractures. Group 1 underwent bridging external fixation with a Pennig device; group 2 underwent manipulation and plaster immobilisation. All patients were initially treated for 6 weeks and reviewed regularly for 12 months.

At a mean of 7.8 years 86 fractures were available for review (36 treated by fixator and 50 treated in plaster). They were assessed to determine the anatomical and functional outcome of their wrist and also the incidence of post-traumatic degenerative change.

The patients had standard anteroposterior and lateral radiographs taken, to allow standard measurements to be made. The degree of arthritic change was also documented. An independent physiotherapist carried out a functional assessment, consisting of range of movement and grip strength in both wrists.

A Gartland and Werley demerit score was calculated, 94% of patients in each group had an excellent or good outcome. Patient satisfaction was comparable, 94% in the fixator and 92% in the plaster group were entirely satisfied.

Although a significant difference was found in terms of radial shortening between the groups, favouring the fixator group (p< 0.05), shortening of > 2mm did not adversely effect the functional outcome. However bridging external fixation did not improve the dorsal angulation in this study. No other radiological or functional parameter showed a statistical difference between the groups.

One patient in this series developed symptomatic post-traumatic arthritis. Grade 1 radiological signs (Knirk & Jupiter) occurred in 25% of patients but only half of these had sustained intra-articular fractures.

In conclusion: no overall long term benefit has been found to treating Colles’ type distal radial fractures with bridging external fixator as compared to plaster immobilisation.

External fixation of distal radius fractures usually involves the use of a bridging fixator. However, immobilisation of the wrist can be associated with various complications and therefore dynamic external fixators were developed to allow wrist mobilisation with the fixator in place. But dynamic fixators themselves are not without complications and more recently interest has been rekindled in non-bridging external fixators (otherwise called metaphyseal or radial-radial fixators).

Following a pilot study using a non-bridging external fixator (Delta frame) in the treatment of intra-articular distal radius fractures, our aim in this study was to compare the functional and radiological outcome of the Delta frame and a standard wrist-bridging static external fixator in the treatment of such fractures. Sixty patients with intra-articular distal radius fractures were randomly allocated to receive either a static bridging Hoffman external fixator or a non-bridging Delta frame. All patients had the fixator removed at six weeks. Clinical and radiographic assessment was performed regularly up to a maximum of twelve months with the clinical results being expressed in terms of range of movement, pain, grip strength and ability to perform certain activities of daily living. Radiological assessment was performed by an independent radiologist. Mean follow-up was ten months.

The only sustained significant difference in function was a greater range of flexion in the Hoffman group. No significant difference could be detected between the two groups in terms of the radiological outcome. Complications included pin-site infection, paraesthesia, extensor pollicis longus tendon rupture and chronic regional pain syndrome. Three patients underwent further surgery. We did not demonstrate any advantage in the use of a non-bridging fixator in the treatment of intra-articular distal radius fractures.

The use of a forearm cast for paediatric buckle fractures of the distal radius is widespread practice. These fractures do not displace and follow-up in Fracture Clinic is only for cast removal. This may mean missed school for the child, or work for parents.

Modern materials allow a robust lightweight back-slab to be used for protection of these stable, though painful, injuries. Unlike a plaster of Paris backslab, Prelude? (Smith and Nephew) is removed by unwrapping the outer bandage. Parents can do this at home.

We prospectively studied 41 consecutive children aged 12 or less with buckle fractures of the distal radius, presenting to Fracture Clinic. After the diagnosis of isolated buckle fracture was confirmed, a Prelude? cast was applied. Parents were given a full explanation and written instructions, which were also sent to the GP. Telephone follow-up was carried out at 3–4 weeks.

Forty of forty-one parents expressed satisfaction with both the treatment and the instructions. The parents of one patient misunderstood the instructions, re-presented to fracture clinic and were dissatisfied for this reason.

With modern casting materials and adequate instructions at Fracture Clinic, routine follow-up of patients with buckle fractures is unnecessary. Resource savings can be made in this way with no compromise to patient care and increased patient/ parent satisfaction.

Our purpose is to use radiographs to compare callus formation with two types of intramedullary nailing for femoral shaft fractures: reamed interlocking (IL) and Ender nails.

Femoral shaft type A fractures according to AO classification were studied.

From 1991 to 1995, 27 patients with 27 fractures were treated with reamed IL nailing and 79 patients with 81 fractures were treated with Ender nailing. IL group included with an average of 22 (range, 16–28) years, and the Ender group included with an average of 28 (range, 15–72) years.

Patients had been followed for an average of 1.8 (range, 1–2.8) years after surgery. In all cases of IL group, the femoral canal was reamed. For type A3 fractures, an interlocking screw was inserted only at the distal site. For type A1 and A2 fractures, both proximal and distal locking screws were placed. In the Ender nailing cases, 3 to 5 Ender nails were inserted from medial or lateral side of the supracondylar or intertrochanteric regions of the femur as was dictated by the fracture site. All of these fractures were reduced by a closed technique. The measurement of postoperative callus area was calculated from the maximum cross-sectional area on the anteroposterior and lateral radiographs.

Fracture healing was successful in all patients. On the radiograph, the callus for the IL group appeared at a mean of 3.9 weeks after surgery, and at a mean of 2.8 weeks for the Ender group. In the IL and Ender groups, fracture healing was noted at a mean of 3.4 and 2.0 months, respectively. The mean area of callus formation in the IL and Ender nailing was 439.5mm2 and 699.4 mm2, respectively. To compare the two groups by using a Mann-Whitney U test, the significant differences were seen in the callus appearance period (p< 0.05) and in the callus area (p< 0.01).

Dynamization at the fracture site is reported to increase external callus formation.

Our results indicate that the elasticity of the fixation obtained with Ender nailing promotes callus formation.

We developed a new type of bioactive bone cement, CAP (Hydroxyapatite composite resin; composed of 77% w/w hydroxyapatite granules and bisphenol-A glycidyl methacrylate-based resin) for bony defect filling. Elastic modulus of CAP is similar to a cortical bone, while it is injectable before hardening and physiologically bonding with bone in 4 to 8 weeks. We present a new method of treatment for unstable Colles’ fracture with this material in clinical use.

Experimental comminuted Colles’ fracture was produced in three fresh frozen cadavara. Fracture was reduced and fixed percutaneously with K-wires. 4.5mm drill hole was opened on the radial cortex 3cm proximal to the fracture site. Comminuted fragments were pushed-up to the subchondral area with a blunt rod and CAP was injected through the same way. After cement hardening, K-wires were removed. X-ray photos were examined before fracture, after fracture and after reconstruction with CAP, in order to evaluate the shape of the radius. CT was examined to evaluate the placement of CAP.

Radiographic parameters of radii were well recovered after reconstruction with CAP. Over correction of the radial length was observed in one bone but good reduction was generally achieved (Table). This means realignment of the distal radioulnar joint, which results in good outcome clinically. In transverse section of CT, 41 to 69% (average 55%) of subchondral area was filled with CAP. Filling of CAP was better in an osteoporotic bone. These results show the usefulness of this material for treatment of unstable Colles’ fracture especially in osteoporotic patients.

To assess patient/parent satisfaction with treatment of radial Forearm Buckle Fractures without the necessity of fracture clinic visits.

A+E staff were provided with definitions and suitable example X-Rays of radial forearm buckle fractures. The A+E staff were asked to mark the films with a green dot for Radiological review if the patient was included in the study, and these films were seen within 24 hours by a consultant radiologist.

Over a three month period all patients with radial forearm buckle fractures seen in A+E were treated with an Alder Hey splint rather than plaster, they were then given a fracture clinic appointment for three weeks later. At this visit the medical staff completed a proforma with the following information, appropriateness of the diagnosis, side, bone/cortex involved, degree of angulation as well as the mode of injury.

The patients and their parents were asked whether they were happy with the level of support that the splint gave and whether they would have been happy to remove the splint without visiting the fracture clinic.

72 (86.7%) had suffered low energy injuries, 5 (6%) high energy injuries, 5 (6%) did not attend their clinic appointment.

65 of 78 (83%) of parents and 65 of 72 (90%) of patients felt that the level of provided support was adequate (6 patients too young to answer)

58 of 78 (74%) of parents and 53 of 72 (74%) of patients would have been happy to make the decision to remove the splint themselves (6 patients too young to answer)

5 (6%) of the diagnoses were deemed to be inappropriate, of these 2 were picked up in radiology review and sent to clinic and 3 were soft tissue injuries.

We feel that the results show that the majority of patients with radial forearm buckle fractures (appropriate guidelines available to A+E staff) do not need to be seen in the fracture clinic, as long as their X-Rays are reviewed and any inappropriately diagnosed fractures sent to clinic. This has significant implications both for fracture clinic workload and also financially for hospitals.

The main object of acetabular revisions is to restore bone stock and provide adequate support for the cup. Allograft bone has been used to reconstruct the acetabulum with variable results. This study is a prospective assessment of the performance of the uncemented cups with morsellized allograft bone in revision acetabular reconstruction.

A single surgeon using a direct lateral approach performed 98 acetabular revisions. An uncemented hemispherical cup with multiple screw holes and morsellized allograft bones was used in all the reconstructions. Patients were clinically assessed by Harris Hip score. Acetabular defects were classified by AAOS Classification system using standard AP pelvis x-rays. Massin’s criteria was used for assessing cup migration; evidence of screw breakage and acetabular bone incorporation were also looked for.

5 patients died before the 3-year follow-up, leaving 93 hips for final analysis. Mean age at surgery was 66 years (range 24–87). Majority of the acetabular defects belonged to AAOS type III. The mean follow-up was 76. 13 hips have undergone repeat revisions, five of which for aseptic loosening of the cup. Meantime to revision was 42 months.

Reconstruction of the bone-deficient acetabulum in revision arthroplasty of the hip is a difficult problem and no single procedure is universally good. However, the use of allograft bone provides a biological solution by restoring the bone stock. The use of uncemented cups with screws provides the primary stability that is supplemented later by the incorporated allograft bone. The rate of revisions for aseptic loosening of the cup in our series is low at 6% after a mean of 6 years. Even in these cases the repeat revisions were significantly easier due to restored bone stock.

To assess primary and revision knee arthroplasty revision activity in a single English health region, and identify trends and reasons for revision surgery.

Surgeons performing knee arthroplasty surgery in Trent Region (Population 5.13 million: 16 hospitals : 107 Consultant Orthopaedic Surgeons) provide the Trent Arthroplasty Audit Group with patient and operative details by completing a standard proforma. Data capture is optimised by a peripatetic clerk checking theatre and admission records in each hospital

18762 primary knee arthroplasties were performed in Trent Region in the period 1990 – 1999.

949 revision knee arthroplasties were performed between 1992 and 1999.

In the last 10 years the number of TKA’s implanted in patients aged 55 yrs or less increased by 300%, there was a corresponding increase of 380% in patients aged 85 yrs. or over whilst the number of patients who had their knee replaced for rheumatoid arthritis decreased by 59%. 83% of patients are satisfied with their TKA when questioned 1 year post surgery. 52 of the 87 surgeons who perform TKA revision perform less than 1 per year whilst 30% of the revisions are performed by 4 surgeons in this region. The reasons for revision TKA were:

5% of knees revised for infection required further revision surgery for recurrence of the infection.

The Trent Knee Arthroplasty Register has the potential to help us evaluate TKA outcome and set standards in a U.K. settting.

We present the mid term results of 267, 3M Capital hip replacement performed in a single institution from 1991 to 1994. Patients were recalled back to clinic in April 1998 after the reported high failure rate of 3M hips. Fifty- nine hips were excluded from this study for various reasons.

Average follow-up was 68.8 months. Nine (4.2%) have been revised for aseptic loosening at the time of review and further 10(4.8%) of the stems are radiologically loose. There was no statistical significant difference between hips that failed, regarding grade of the operating surgeon, surgical approach: trochanteric osteotomy or Hardinge, or type of prosthesis used: monoblock (stainless steel) or modular (titanium). Acetabular wear rate, width of medial cement mantle or cancellous bone at level of neck at Gruen zone7, or stems with canal fill index less than 50%, 7 cm below the level of the collar also showed no statistical difference. Male patients had higher incidence of loosening (p=0.001) which was statistically significant. Both varus and valgus alignment of the stem had higher failure rate which was significant. We could no find any obvious reason for failure in 10 of the 18 patients. The stem was either in varus or there was an inadequate cement mantle in 8 of the failed hips on the initial postoperative radiograph. A feature of this study was high incidence of endosteolysis and debonding of prosthesis from cement in the failed cases.

The present series showed considerably lower revision and loosening rate of 3M stems compared to the published series, the reason for which is not clear. Only Palacos cement was used in this series, which may partly account for the lower failure rate. Surface finish of the stem leading to debonding of the prosthesis from cement along with different modulus of elasticity probably accounts for the higher rate. Technical failure is partly to blame for the higher failure rate.

To report a 15-year survival analysis of the Oxford Medial Unicompartmental Knee Arthroplasty (Oxford UKA) in an independent series.

We report the results of a series of 420 Oxford UKAs performed between 1983 and 2000. Indications for surgery were primary antero-medial osteoarthritis of the knee with an intact ACL, correctable varus deformity of < 15° and < 15° fixed flexion deformity. The state of the patello-femoral joint was not used as a selection criterion. Patients were contacted by a postal questionnaire or by telephone. The outcome of all 420 knees was established, with none lost to follow-up. Seventy-six knees were in patients who had died and the state of each arthroplasty was determined from hospital and GP records.

Seventeen patients (4%) had required revision. Indications for revision were lateral compartment arthrosis (7), component loosening (4), bearing dislocation (4) and infection (2). There were no failures for polyethylene wear. Cumulative survival at 15 years was 94.3% [95% CI 3.8%]. The worst case scenario was 94.3% as none were lost to follow-up.

The results from an independent series are important, as they avoid bias. The 15-year results of this independent series are better than any other reported series of unicompartmental device at 15 years and as good as the published independent 15 year survival results for total knee arthroplasty. The data illustrates that excellent long-term survival can be achieved with the Oxford UKA, allowing patients to benefit from the advantages that unicompartmental arthroplasty offers. We believe that provided patients are selected appropriately, this device provides the treatment of choice for anteromedial osteoarthritis of the knee.

Cementless fixation for total knee arthroplasty (TKA) has been proposed as an alternative to cemented for several reasons, of which the most important is the possibility of increased survival. The purpose of this study was to compare the ten-year survival of TKA in a unique prospective randomised trial of cemented versus cementless fixation.

A consecutive series of patients was randomised to undergo either cemented or cementless Press-Fit Condylar (PFC®) TKA. There were 219 patients (277 TKA) in the cemented group and 177 (224 TKA) in the cementless group. There were no significant differences in age, gender or diagnosis between the two groups.

A single surgeon (PJG) performed or directly supervised all operations. The prosthesis used in all cases was the posterior-cruciate-retaining PFC® knee replacement system. Independent clinical review was performed at six months, annually until five years, and finally at ten years after surgery. Using revision surgery as the end-point, logrank analysis was used to compare the ten-year survival of the two groups.

The mean interval of follow-up was 6.3 years (range, 2.0–11.7). At the last review, 104 patients (138 TKA) had died, without need for revision. All patients were traced and there was no loss to follow-up. In the cemented group, seven arthroplasties were revised; five for infection and two for exchange of polyethylene inserts. Ten-year survival was 96.5% (95% CI, 90.9–98.7%). In the cementless group, six arthroplasties were revised; three for aseptic loosening, one for infection, one for instability and one resizing for anterior knee pain. The ten-year survival was 96.6% (95% CI, 89.6–98.9%). There was no significant difference in the survival of the two groups.

The long-term survival of cementless PFC® TKA is not significantly different from their cemented counterparts. The use of less expensive cemented implants, therefore, can make a significant impact on health resource planning.

Polyethylene wear can be an important cause of knee replacement failure.

Six TKRs in young, active patients with excellent Oxford Knee Scores and Knee Society Scores, mean 76 months post knee replacement and 5 control patients, 2 weeks post TKR, were selected. Each patient had weight bearing stereo radiographs of at 0, 15, 30, 45 and 60 degrees of flexion while standing in a calibration grid. These x-rays were analysed using our Radio Stereometric Analysis (RSA) system. The three-dimensional shape of the TKR (manufacturer’s computer aided design model) was matched to the TKR silhouette on the calibrated stereo radiographs for each angle of flexion. The relative positions of the femoral and tibial components in space were then determined and the linear and volumetric penetration was calculated using Matlab software.

The accuracy of the system was found to be 0.3mm (CAD model tolerance 0.25mm). The mean linear wear in the control patients was 0.02mm (range −0.19 to +0.23mm). Average linear penetration in the study group was found to be 0.6 mm at 6 years, giving an overall linear wear rate of 0.1mm/year. Average penetration volume at 76 months was 399mm3. The average volumetric wear rate was 63mm3/year.

It is possible to measure volumetric wear in vivo using RSA. Volumetric wear rate was found to be 63mm3 per year. Studies on retrieved normally functioning hip replacements have shown volumetric wear rates of 35mm3 per year. However, clinical outcomes of knee replacements are comparable to those of hip replacements, suggesting that the knee has a more effective mechanism for dealing with polyethylene wear particles.

To document the incidence of intra-articular pathology resulting from delayed Anterior Cruciate Ligament (ACL) reconstruction

A prospective assessment of meniscal and chondral damage found at the time of primary ACL reconstruction, and the relationship of incidence of intra-articular pathology to time since original ACL injury.

We reviewed 1960 patients who had undergone a primary ACL reconstruction. There were 1443 Males and 517 females, with an average age of 28.3 years. The average age at injury was 25.4 years.

1136 patients (58%) had secondary intra-articular pathology, 621 (54.7%) had a medial meniscal tear, 594 (52.4%) had a lateral meniscal tear and 381 (33.5%) had chondral damage. The average time from injury to reconstruction was 2.9 years (34.8 months) Those with secondary intraarticular pathology presented for reconstruction later, average 3.9 years (46.8 months), compared to those without secondary pathology, average 1.5 years (18 months).

The incidence of secondary intra-articular pathology increased with delay between original ACL injury and reconstruction. 41% of those waiting 12 months; 60% of those waiting 3 years; 79% of those waiting 5 years and 88% of those waiting 10 years had secondary intra-articular pathology.

This study confirms the relationship between an unstable ACL deficient knee and the incidence of secondary intra-articular pathology. Furthermore, our study reveals the increasing incidence of meniscal and chondral pathology the greater the delay from injury to ACL reconstruction. To prevent unnecessary secondary intra-articular pathology we recommend ACL reconstruction is performed with minimal delay.

The pathophysiology of discogenic low back pain is poorly understood. The morphological changes occurring in disc degeneration are well documented but unhelpful in determining if a particular degenerate disc will be painful or not.

Herniated intervertebral disc tisssue has been shown to produce a number of pro-inflammatory mediators and cytokines. No similar studies have to date been done utilising disc material from patients with discogenic low back pain.

The aim of this study was to compare levels of production of interleukin-6 (IL-6), interleukin-8 (IL-8) and Prostaglandin E2 (PGE2) in disc tissue from patients undergoing discectomy for sciatica with that from patients undergoing fusion for discogenic low back pain.

Tissue from 50 patients undergoing discectomy for sciatica and 20 patients undergoing fusion for discogenic low back pain was cultured and the medium harvested for subsequent analysis using an enzyme linked immunoabsorbent assay method. Statistical analysis of the results was performed using the Mann-Whitney test.

Disc specimens from both experimental groups produced measurable levels of all three mediators. Mean production of IL-6, IL-8 and PGE2 in the sciatica group was 26.2±75.7, 247±573 and 2255±3974 respectively. Mean production of IL-6, IL-8 and PGE2 in the low back pain group was 92±154, 776±987 and 3221±3350 respectively (data = mean production pg/ml ± 1 standard deviation).

There was a statistically significant difference between the levels of IL-6 and IL-8 production in the sciatica and low back pain groups (p< 0.006 and p< 0.003 respectively).

The high levels of pro-inflammatory mediator production found in disc tissue from patients undergoing fusion for discogenic LBP may indicate that nucleus pulposis pro-inflammatory mediator production is a major factor in the genesis of a painful lumbar disc. This could explain why some degenerate discs cause LBP while other morphologically similar discs do not.

The role of posterior cruciate ligament (PCL) in total knee replacement (TKR) has been a matter of debate for long time and remains controversial. In this study, the effect of posterior cruciate ligament (PCL) sacrifice on the tibiofemoral joint gap was analysed in 30 varus osteoarthritic knees undergoing posterior stabilized total knee replacement. Medial soft tissue was released and bone cut was made without preserving the bone segment of tibial PCL insertion. Then the medial and lateral joint gaps in full extension and 90□& lsaquo; flexion were measured before and after PCL sacrifice using a tensioning device (V-STAT tensor(tm), Zimmer). After PCL sacrifice, the flexion gap significantly increased both in medial and lateral side (4.8 □} 0.4 and 4.5 □} 0.4 mm respectively, mean □} SE) compared to those seen in the extension gap (0.9 □} 0.2 and 0.8 □} 0.2 mm, p < 0.001 ANOVA). There was no significant difference between the changes in the medial and lateral gap (p = 0.493). In conclusion, results of this intraoperative measurement showed that PCL sacrifice leads to a selective increase in the size of flexion gap by an average of 4.7 mm whereas it had little impact on the correction of varus deformity. These findings provided insights as for the role and necessity of PCL sacrifice in the correction of varus and flexion deformity. Because the flexion gap surpassed the unchanged extension gap during PCL sacrifice, PCL release could be used as a surgical technique to balance the gaps without additional bone cut.

The purpose of this paper is to emphasize lateral compartment arthroplasty as efficient method and to discuss postoperative problems by investigating mid-term results (over 5 years)

Two hundred and twenty two consecutive unicompartmental knee arthroplasties (UKA) were performed in our hospital between August 1977 and December 1999. Thirty eight joints of 37 patients underwent lateral UKA. There were 8 male and 29 female patients with an average of 65.1 years old. The following prostheses were used: Marmor in 5 patients, Oxford in 1, PCA in 11, and Omnifit in 21. Out of them, 24 joints had follow up over 5 years after replacement. Three patients died of unrelated illness and 3 were lost to follow up. The remaining 18 joints could be followed from 60 to 189 months (average, 99 months). The knee score of the Hospital for Special Surgery (the HSS knee score) was used for clinical evaluation.

Clinical results by the HSS knee score showed that 2 joints were judged as “good”, 13 as “fair”, and 3 as “poor” before surgery. After surgery 13 joints were improved to “excellent”, 3 to “good”, and 2 to “fair”. The two joints with fair results had revision surgery. In all, 16 joints had satisfactory results. With radiological evaluation, the average preoperative alignment on standing was 14.9o of valgus angulation and corrected to 6.9 o of valgus. Although radiolucent lines under the tibial component were not found, a radiolucent line was observed and extended to loosening in one femoral component. This patient was successfully revised to another type of UKA 3 years after the index surgery. In the medial compartment, we found slight deterioration of osteoarthritic change in 5 joints. Of these, one patient, needed medial UKA.

Lateral UKA is a reliable and successful option compared with other procedures in a patient with low level of physical activity, because the long-term results tend to last and loosening of the tibial components has not been observed as commonly as in medial UKA. However, deterioration of the medial compartment may occur. The alignment after surgery must be in slight valgus for a satisfactory long-term result.

Percutaneous radiofrequency neurotomy of the lumbar medial branch is a widely accepted treatment for pain of the lumber intervertebral joints. However its success rate has varied among authors. One reason for this inconsistency is the lack of method for objective evaluation of whether the nerve has been sufficiently denervated or not. This study has made possible real time and accurate monitoring of whether electrocauterization is properly executed or not.

The subjects were 50 patients with law back pain persisting for 3 months or longer in whom facet block or medial branch block of posterior ramus was only temporarily effective. They ranged in age from 19 to 76 years (mean 54 years) and were followed up for 1 year to 7 years and 1 month (mean 2 years and 9 months). In our percutaneous radiofrequency neurotomy, the target point of denervation is defined as the groove between the mammillary process and accessory process (1) and complex muscle action potentials (CMAPs) of multifidus muscles are used as an index for objective evaluation of the effects of denervation.

Improvements were observed immediately after the treatment in 39 patients (78%). The effects of this treatment, once attained, remained over a long period, and the duration of effects was 18–20 months as estimated by the cumulative success rate calculated using the Kaplan-Meyer method.

Patients must be carefully selected for percutaneous radiofrequency neurotomy to be consistently effective, all the more because the procedure is simple. However, it is a reliable method for denervation of the lumbar medial branch and long-term relief from pain can be expected. This therapy, therefore, is an effective alternative for the treatment of chronic pain due to lumbar intervertebral arthropathy that resists conservative treatments and disturbs daily living.

Back pain may be related to abnormal segmental movement and suggested treatment is segmental fusion. Recent techniques using cages can achieve fusion rates of over 90% but the clinical results are no better. We hypothesise that the cages integrate fully to adjacent vertebrae taking all the load, producing abnormal stress patterns in the vertebrae producing pain.

In this study a simple FE model of a disc and its adjacent vertebral bodies was developed using ANSYS software. The dimensions of the model were based on those of a human lumbar disc. The normal disc was modelled as having nucleus with fluid properties (bulk modulus 1720 MPa). To model the degenerate disc, the material properties of the nucleus were changed to be the same as the annulus (Young’s modulus, E=5 Mpa; Poisson’s ratio, n=0.49). To model fusion of the disc, the nucleus was replaced with a simple representation of a one of three of the commonly used cages. In all the models the material properties of the cancellous bone (E = 100 MPa; n = 0.3) and the cortical bone (E=12000MPa;n=0.3) remained the same. The model was loaded axially with 1.5 kN.

The vertical and horizontal stress patterns around a loaded degenerate disc showed areas of increased loading in the endplate and cancellous bone. The inclusion of cages in the model showed high concentration of tensile and compressive stresses at the point of contact with the cages and in the cancellous bone of the vertebral bodies. The stress pattern showed more similarity to that of degenerate disc, than a normal one.

Fusion cages alter the pattern of stress distribution in the adjacent vertebral bodies from that of the normal disc. The excellent fusion rates of the cages are not mirrored by improvement in clinical results. It supports the concept that abnormal load transfer may be a more significant cause of back pain than abnormal movement.

Surgical repair of rotator cuff tendon is one of the most common orthopaedic procedures performed in the United States. This prospective single-surgeon study reports the long-term results of chronic rotator cuff repair. Vigorous statistical analysis was carried out to detect any association of various outcome parameters with the exact surgical pathology.

105 consecutive shoulders (97 patients) undergoing open repair of chronic (> 3 months) rotator cuff tear between 1975 to 1983 by the senior author were recruited to the study. Pain unresponsive to nonoperative treatment was the indication for surgery. The details of patient’s medical records, radiographic data, and the operative findings were prospectively reviewed. There were 67 males and 30 females with a mean age of 58 years (range, 38 to 75). Follow-up averaged 11 years with no patients lost to follow-up. There were 16 small, 40 medium, 38 large and 11 massive tears.

Surgical repair relieved pain in 92% of patients (p< 0.0001). There was also a significant improvement in range of motion (p< 0.0001) and strength of abduction and external rotation following surgery (p< 0.0001). Return of movement and strength decreased with increasing tear size. At the latest follow-up results were rated as excellent in 68 shoulders, satisfactory in 12, and unsatisfactory in 25. 8 out of the 11 massive tears had unsatisfactory outcome. There were eight reoperations for traumatic retears.

Standard tendon repair techniques combined with adequate postoperative protection and monitored physical therapy produced consistently satisfactory results. Introduction of experimental repair methods should be confined to those patients with massive tendon tears and only then with the hope of increasing function, as pain relief is satisfactory with usual treatment methods.

Arthroscopic acromioplasty is said to be a difficult procedure to learn although Gartsman stated that most surgeons can reliably perform an arthroscopic decompression after instruction in 10–20 cases. We assessed the learning curve for one consultant surgeon.Patients were selected on the basis of clinical examination and all had signs of impingement at arthroscopy. Surgery was performed between February 1993 and June 1996. Patients with full thickness tears were excluded from the study. The senior author had not performed any arthroscopic acromioplasties prior to providing a service in this hospital. Each shoulder was assessed immediately prior to surgery and at follow up using the Constant and Murley method of functional assessment without the power component. Patients were asked if they would have the operation again, with the benefit of hindsight.Of 89 shoulders complete preoperative and postoperative scoring beyond 6 months was available in 71. Of these, 62 operations were performed by one consultant (ANS) and 9 by trainees under his guidance. Patient questionnaires were completed for 73 of 89 shoulders.

A standard operative technique under general anaesthesia was used for all patients.

The overall improvement in shoulder function was 10.3 (SD 12.4) points (p< 0.0001). The change in shoulder score did not vary with increasing surgical experience. The length of operation, however, shortened with increasing experience with a mean of 106 minutes and 60 minutes for the first and last five operations. Questionnaire analysis found 82% would have the operation again.

In our study operative time reached a plateau after approximately the first twenty five cases but the results of these early operations are good.

The aim of this study was to review the effectiveness of percutaneous release of the common extensor origin for tennis elbow. The operative technique is similar to that previously reported by Hohmann in 1949.

There were 29 patients (31 elbows) that underwent the procedure between 1991 and 1998. There were 14 males and 15 females; 19 were right handed, and 17 had the dominant arm involved. The mean age was 51.8 years (range 34–65); the mean duration of symptoms was 21.7 months (range 8–60 months). All patients had a minimum of 12 months of conservative treatment including NSAIDs, splinting, physical therapy and local anaesthetic and steroid injections (2–6 injections). All operations were performed as day case procedures, with the majority (25) done under local anaesthetic. 24 patients were independently reviewed using Hospital for Special Surgery Elbow Assessment and a questionnaire. Grip strength measurements were performed using JAMAR Dynanometer and the level of patient satisfaction was recorded.

5 patients could not attend the special review clinics. They were contacted over the phone and necessary data recorded. The mean follow up was 45.2 months (range 8–88 months). 24 patients scored above 70 points and were very satisfied, 6 patients were considered failures as their symptoms warranted formal open release operation; only two reported an improvement following the open releases, with the remainder still symptomatic at the last follow up. An overall success rate of 81% was recorded. Complications were rare - one patient who had bruising of forearm after the procedure.

In conclusion this procedure can be recommened as an efficacious first line of surgical treatment, with advantages of being safe, quick to perform and with minimal morbidity.

Lumbar Degenerative Kyphosis (LDK) is a clinical entity showing kyphosis in the lumbar spine in elderly with multilevel disc narrowing and a varied degree of osteoporosis. LDK patient complains of stooped gait with persistent low back pain and weakness. Purpose of this paper is to study the lumbar muscle in LDK patients with histopathologic and biophysical evaluations to investigate the pathogenesis.

Materials and Methods: 1. Intramuscular pressure (IMP) (a) of the lumbar extensor compartment and hemoglobin content (Hb)□@(b) of 25 young volunteers were also investigated comparing in standing upright and flexion positions using (a)□@pressure monitoring kits and an non-invasive oxygenation monitor. 2.Muscle biopsy specimens obtained from the lumbar extensors of 9 LDK patients were histopathologically examined with HE, cytochrome c oxidase and other methods. These data were compared with muscles taken from age-match controls. Mitochondria function was also examined on biochemistry.

1. IMP of the extensors markedly increased in the flexion position (130.0□}45.4 in males and 86.3 mmHg in fem.) comparing to straight upright□@(22.8□}14.4, 17.0□}6.0). Oxy-Hb concentration decreased from 100% to 92.9, 95.5 % respectively in flexion, which was a sign of ischemia. 2. Both multifidus and sacrospinalis m. showed moderate to marked interstitial fibrosis, decreased number of muscle fibers and decreased stain intensity of cytochrome c oxidase. These finding were similar to those seen in repeatedly compressed muscles of an animal model of the chronic compartment syndrome. In comparison the rectus abd. and psoas muscles in the patients showed almost normal except for some aging changes. Conclusion: There appeared to be definite atrophy of the lumbar extensor muscles with histochemical and biochemical methods in LDK patients, whereas the flexors showed no change. This extensor atrophy is limited in the lumbar region in LDK. These localized atrophy of the lumbar extensors would suggest a result of high IMP during working in deep bending position of the spine for many years and may play important role in etiology of this disease condition.

This paper reports two studies of uncemented (UC) shoulder arthroplasty – one directed at UC humeral stems (Study 1) and the second at UC glenoid components (Study 2).

In Study 1, 160 consecutive UC humeral stems were inserted between 1989 and 1995. Three types of stem were used – Biomodular, modified Biomodular and Nottingham. At a mean follow-up of 4.3 years 18 shoulders were lost to follow-up. Of the remaining 142 shoulders radiographs from routine follow-up appointments at 6 months,1,2,3,5,7 & 9 years were reviewed together with a clinical follow-up of the patients.

In Study 2 a survival analysis was carried out on a consecutive series of 222 UC glenoid components inserted between 1989 and 1998 at a mean follow-up of over 5 years. Survival was defined as a prosthesis remaining in situ in a live patient. Six types of UC glenoid component were used – Copeland/Zimmer(non HA), stndard Biomodular, low-profile Biomodular, Nottingham prototype, Nottingham and Nottingham with HA.

In Study 1, radiological follow-up indicated 3 stems(2%) showed definite loosening (all related to deep infection) – all were revised. Six stems (4%) showed probable loosening but were asymptomatic.

In Study 2, for the whole series a survival table was created which identified a survival at 2; 5 and 10 years respectively of 92%; 75% and 66%. The later prosthesis designs performed best. A radiological analysis of all shoulders is currently in progress. This audit of outcome has indicated that hydroxyapatite has been beneficial but further long-term studies are required.

100 pre-operative and post-operative knee and function scores were analysed to assess whether a low pre-operative score was related to a poorer outcome, ie, are we operating too late? A two tailed student “t” test was performed showing that a pre-operative “function “ score of less than 30, resulted in a lower post-operative “function” score and the difference was statistically significant. These patients also showed the greatest improvement in scores and were the most satisfied with surgery. However, a low pre-operative “knee” score could not be related to a low post-operative “knee” score. Patients who had either a “knee” or “function” score of greater than 60 made no statistically significant improvement in either score. In conclusion, the pre-operative “knee” score is not a reliable indicator for when to perform surgery. However, the “pre-operative “ function score should be given more credence, along with clinical judgement, as it would appear that operating too late adversely affects the functional outcome of total knee arthroplasty.

The aim of this study was to evaluate the morbidity associated with carpal tunnel syndrome and the outcome following surgical treatment using the Nottingham Health Profile (NHP).

Between 1994 and 1996 we performed a prospective study of the effect of carpal tunnel release on the health status of 96 patients. The Nottingham Health Profile, a validated generic scoring system was used to assess quality of life, before and after surgery.

96 patients with 103 symptomatic hands were studied over this two year period. The patients completed a questionnaire before and 4 months after surgery. The notes were reviewed by an independent assessor and data collected with regard to duration and nature of symptoms, associated conditions, patients’ satisfaction and complications.

72 patients were satisfied with the results of surgery and 24patients were dissatisfied despite in the main clinical improvement. There was a significant improvement in the scores for pain, physical mobility and sleep 4 months following surgery in all patients.

We observed that those patients with a significantly high pre-op NHP score fared less well than cohorts, developing more frequent complications and overall were more likely to be dissatisfied with the results of surgery. This group of dissatisfied patients had previously been indistinguishable from their cohorts and were as it were invisible. The high NHP scores provided an objective way of identifying this group of individuals.

Carpal tunnel syndrome had a notable impact on the health status of our patients. There was a significant improvement in the NHP scores 4 months following surgery.

Our findings show that outcome assessment tools have predictive value in identifying patients who may not benefit from surgery or in whom a poor result might be anticipated.

The application of arthroscopic procedure for osteoarthritic knee is limited to rather initial stages of the disease. Here we report the results of new arthroscopic procedure, which was named arthroscopic posteromedial release, applied to relatively severe cases of medial type osteoarthrits (OA)

Forty-eight knees of 46 patients of OA knees with flexion contracture were treated with arthroscopic posteromedial release. Thirty-two were female and 14 were male. All the patients had been treated conservatively beforehand. The mean age of the patients was 71.6 (range, 47 to 84 years), the average range of motion was 13 to 129 degrees. Only one case was classified stage II in Kellgren Lowrence x-ray classification, 13 and 34 cases were stage III and IV respectively. The average femoro-tibial angle was 183.4+-4.4 degrees.

In surgery, we release the joint capsule along with the medial tibial condyle, arthroscopic debridement including medial meniscentomy was performed at the same time. If some cases, medial collateral ligament was cut transversely to obtain enough joint space. We use hyaluronan intra-articularly once a week for 5 weeks postoperatively. Patients were examined at 3,6,12,18 and 24 months after surgery and evaluated subjectively and objectively with the rating system of Japanese Orthopaedic Association knee score (JOA score). Clinical results were also classified excelletn, good, fair and poor by our criteria.

Eighty-three per cent (40 knees) of patients were satisfied at their last follow up. Sixty-seven percent (32 knees) of the patients were excellent or good. Six knees were converted to TKA because of their persistent knee pain. Twenty-eight knees complained of night pain pre-operatively, but only four of them complained of it postoperatively

Considering that most of the patients in this series were grade IV in x-rays and their joint surface of medial compartment showed large eburnation both femur and tibia, TKA is most preferable treatment conventionally. But our results showed this arthroscopic technique was one of the applicable choices for severe OA knees.

65 patients over the age of 80 years, who underwent a total knee arthroplasty between 1989 and 1994, were retrospectively reviewed, by means of questionnaire, phone call, clinical and radiological examination.Notes were reviewed for pre-existing medical conditions, pre-operative and post-operative Knee Society “Knee” and “Function” scores. They were then compared with 65 randomly selected patients in a different age group, 70 years and under.56 octogenarians were alive at 5 years and 50 available for full review.

Elderly patients had more pre-existing medical conditions, with hypertension a ubiquitous diagnosis, required a longer in patient stay and more social services input before discharge, than the younger age groups. All patients in the elderly group suffered from osteoarthritis, unlike the younger age groups. Valgus deformity of the knees was only seen in the younger cohort. Previous surgery was more common in the octogenarians, with more octogenarians having undergone a tibial osteotomy and more youngsters undergoing arthroscopy. A reflection of changing surgical practice.

“Knee” Scores were not significantly different between the age groups. However, the “function “ scores pre-operatively, were significantly lower in the over 80s and they made a more significant post-operative gain. Post-operatively, elderly male patients were more likely to go into retention post-operatively, than female patients and males in the younger age group.

None of the prostheses had required revision in the elderly age group and only 5 patients had died since the surgery. None of the deaths were related to the surgery.

We recommend pre-operative catheterisation of octogenarian patients, especially those with a history of prostatism. There would appear to be from this review no indication for denying elderly patients an arthroplasty on the basis of age.

To assess total knee arthroplasty function in osteoarthritic patients who had their arthroplasty aged 55 years or less.

Self administered questionnaires were posted to 150 patients who had been registered on the Trent Regional Arthroplasty Register as having their TKA for osteoarthritis aged 55 or less. 85% of questionnaires were returned completed giving us information on 136 TKAs. The mean age of the patients at TKA was 51 yrs (Range 29 – 55 yrs.). Male 60: 67 Female. The mean follow-up was 44 months.

41% of patients had had no knee surgery prior to their TKA. 9 had had a corrective osteotomy.

51 patients had to give up work because of their osteoarthritic knee, only 17 got back to work after their TKA. 80% of patients felt that their arthroplasty had met or exceeded their pre-operative expectation in relieving pain though 41% continue to experience moderate or severe knee pain and 29% continue to have regular night pain. 62% of patients felt that they had been able to resume leisure activities to the same or better level than expected pre-operatively.

Volar wrist ganglion has a different mode of origin and higher complication rate after excision compared to its dorsal counterpart. This study, which is part of the Trent region ganglion audit, was carried out to prospectively evaluate the natural history and treatment outcome for volar wrist ganglia.

Patients were invited to join the study between 1993 and 1995 following initial consultation with either an orthopaedic or plastic surgeon. Questionnaires were sent within the first year, at two years and finally at five to six years. The final review included a Patient Evaluation Measure (PEM) questionnaire.

Of the 234 patients initially consulted, 186 joined the study, 155 of these responded, 122 at final review and 109 at year two. There were 98 females and 57 males. Three patient groups were identified:

Group I: natural history (no intervention) (N=38)

Group II: aspiration/injection (39)

Group III: excision group (78)

In conclusion, over half of volar wrist ganglia disappear without any intervention between 2 to 5 years. About 45% recur whether aspirated or excised. There is a 18% complication rate with excision, but neither aspiration/injection nor leaving them alone with reassurance was associated with any complications. Irrespective of the treatment, about 80% of patients are satisfied at five years, slightly more than at two years.

This information may form a basis for patient information before deciding treatment. It could also help general practitioners advise patients before hospital referral.

Increasing emphasis is placed on outcomes research. In this community study knee outcomes scores were evaluated in a ‘normal’ elderly population

The American knee society (AKS), Oxford, and Bristol knee scores were recorded in 100 elderly people without a history of lower limb disorder. The mean age of subjects was 72 years. Mean normalised scores were 90%, 91% and 94% for AKS, Oxford and Bristol knee scores respectively. There were significant negative correlations between knee score and advanced age (p< 0.001) and knee score and co-existent major medical disorders (p< 0.001). The function component was the score component most senitive to these variables (p< 0.001)

Control studies are necessary if knee scores are to be taken as accurate measures of outcome. Comparison of outcome after knee replacement on the basis of knee scores should take account of demographic variables. Scores with a large ‘function’ component appear to be more susceptible to demographic variation.

Between 1982 and 2000, 37 cases of fractures of the odontoid process were treated at Hirosaki University Hospital. There were 16 females and 21 males, with an average age of 43.9 and 37.7 respectively. Twenty-three of 37 were type II and 14 were type III by the classification of Anderson and D’Alonzo. Eight of type II were old fractures. Nineteen of them were injured in traffic accidents, 9 in accidental falls from a height, 4 by falling down, 2 in lumbering accidents and 3 by unknown causes. Severe neurological disorders were recognized in 7, mild in 12 and 22 had no neurological disorders. Neurological disorders were correlated with SAC (space available for spinal cord) at C1-2. Twenty-two of type II (95.7%) and 10 of type III (71%) were treated surgically. Surgical methods were anterior screw fixation of the odontoid process in 7, anterior atlanto-axial joint fixation in 3, posterior atlanto-axial joint fixation in 5, posterior occipito-cervical fusion in 3, anterior and posterior combined fixation of the atlanto-axial joint in 2 and others in 2. Bone union was obtained in 18 (81.8%) of type II and 10 (100%) of type III by the primary operations. There was no nonunion in anterior screw fixation cases. Nonunion occured in one of type II (100%) and 2 of type III (50%) treated nonoperatively. Two of them were operated for nonunion. One of them remained nonunion by two additional operations. No case of nonunion showed neurological deterioration for 91.8 months after treatment on average. Anterior direct screw fixation of the odontoid process is superior to the other methods in the point of immobilization of the odontoid fragment without limiting the motion of the atlanto-axial joint. We recommend anterior direct screw fixation of the odontoid process as a first choice of the surgical method for fresh fractures of the odontoid process in cases with reduced fragments.

Signal intensity changes of the spinal cord on MRI in chronic cervical myelopathy are thought to be indicative of the prognosis. However, the prognostic significance of signal intensity change remains controversial.

The purpose of this study was to investigate the characteristics of MR findings in cervical compression myelopathy that reflect the clinical symptoms and the prognosis and to determine the radiographical and clinical factors that correlate to the prognosis.

The subjects were 73 patients who underwent cervical expansive laminoplasty. Their mean age was 64 years, and the mean postoperative follow-up was 3.4 years. The pathological conditions were cervical spondylotic myelopathy in 42 and ossification of the posterior longitudinal ligament in 31.MRI (spin-echo sequence) was performed in all patients. Three patterns of spinal cord signal intensity changes on T1-weighted sequences/T2-weighted sequences were detected as follows: normal/ normal.

(N/N); normal/ high signal intensity changes (N/Hi); and low signal intensity changes/high signal intensity changes (Lo/Hi). Surgical outcomes were compared among these three groups. The most useful combination of parameters for predicting prognosis was determined.

There were 2 patients with N/N, 67 with N/Hi and 4 with Lo/Hi signal change patterns before surgery. Regarding postoperative recovery, the preoperative Lo/Hi group was significantly inferior to the preoperative N/Hi group. The best combination of predictors for surgical outcomes included age, preoperative signal pattern and duration of symptoms.

The low signal intensity changes on T1-weighted sequences indicated a poor prognosis. We speculate that high signal intensity changes on T2-weighted images include a broad spectrum of compressive myelomalacid pathologies and reflect a broad spectrum of recuperative potentials of the spinal cord. Predictors for surgical outcomes are preoperative signal intensity change pattern of the spinal cord on radiological evaluations, age at the time of surgery and chronicity of the disease.

The Bristol Knee Replacement Registry was established in the 1970’s and contains prospectively recorded data on 3024 patients. The present study examines the group of 812 patients for whom complete pre-operative and five year post-operative data is available in order to relate their eventual health status to the pre-operative demographic data and to disease severity. The group comprised 593 women and 219 men who had undergone either Kinematic, Total or Sled unicompartmental knee replacement.

Pre-operatively, the average American Knee Society Score (AKSS) was 89 with the elderly, rheumatoid patients and women having significantly lower scores.

Five years later the average AKSS had risen to 161 with patients of all ages, (including the over 80’s) gaining considerably. However, the rheumatoid patients remained more disabled as did women who had a final AKSS of 157 as opposed to 171 for the men (p< 0.01). In addition, a statistically significant finding was that those with the lowest pre-operative scores also had the lowest 5 year scores - they never catch up.

173 patients underwent bilateral knee replacement at separate times. Their pre-operative AKSS was significantly higher at the time of the second knee replacement (90) than the first (82) p< 0.01.

We conclude that since patients present earlier for their second TKR and those with most disability fail to catch up the procedure should be performed earlier in the natural history of the disease, especially in women.

In currently used expansive laminoplasty (ELAP) for cervical spondylotic myelopathy (CSM), persistent axial pain, restriction of neck motion and loss of cervical l ordosis have been the significance postoperative problems. To prevent them, the author has developed skip laminectomy in which ordinary laminectomy at appropriate levels is combined with partial laminectomy of the cephalad half of laminae with preservation of the muscular attachments at adjacent levels. Since December 98, the author performed this procedure on 55 patients with CSM who required multilevel posterior decompressions. Twenty-one of these cases with follow-up period longer than 8 months, with an average of 12 months, were observed.

In skip laminectomy, a consecutive four-level decompression between C3/4 and C6/7 as an example is accomplished by removing alternate laminae (C4 and C6), the cephalad half of the C5 and C7 lamina and the ligamentum flava at those four levels. The laminae to be removed were selected after analysis of the pre- and postoperative radiological findings.

Intraoperative blood loss averaged 34 grams. The operation time averaged 128 minutes. The patients were allowed to sit up or walk on the first postoperative day without neck support of any kind. An average recovery rate according to the Japanese Orthopaedic Association score was 63%. None of these patients complained of residual axial pain. The postoperative ranges of neck motion on lateral X rays averaged 87% of the preoperative ranges. The spinal curvature index, according to Ishihara’s method, was reduced in only one of the 21 cases. Postoperative atrophy of the deep extensor muscles measured on T2 weighed axial MRI was minimal.

Skip laminectomy is less damaging to the posterior extensor muscles and its use reduces the postoperative problems commonly seen after ELAP.

Craniovertebral tuberculosis accounts for 5% of all cases of tuberculosis and is the commonest infective pathology affecting this region. There are very few published reports discussing the presentation and management of this complex pathology.

30 cases of craniovertrebral tuberculosis treated between 1989–97 were reviewed retrospectively. The average age was 24 years (range 6 – 42 years) with a follow up of 41 months (range 36 – 48 months). Two main groups on the basis of atlantoaxial stability. 18 (60%) had an unstable atlantoaxial articulation and of these 12 (66%) had a fully reducible AAD in extension. 17 patients (56%) had varying degrees of neurological deficit with lower limb spasticity being the commonest.

Antituberculous chemotherapy, skeletal traction in extension and prolonged bracing with moulded philadelphia collar were main stays of conservative treatment. Surgery in the form of posterior occipito cervical arthrodesis was needed in 13 patients (43%) and indications included incompletely reduced AAD, non resolving neurological deficit and persistent instability despite 6 weeks in traction.

There was 93% success rate with resolution of infection (range 4 – 8 months) and improvement in neurological deficit 2 patients had incomplete neurological recovery and required 2^nd stage anterior transoral odontoidectomy. Management strategies based on the presence or absence of instability and neurological deficit can give a very satisfactory outcome with judicious combination of drug therapy, bracing and surgical decompression with fusion.

All types of cervical laminoplasties for cervical spondylotic myelopathy (CSM) gave the same degree of postoperative neurological recoveries. However, postoperative neck functions differed according to degrees of intervention with posterior supporting elements of the neck (spinoligamentous complex, SLC). To obtain optimal postoperative neck function, SLC should be preserved. Laminar enlargement destroying SLC resulted in anterior tilt of neck, loss of cervical lordosis and loss of cervical range of motion (ROM) by 40–60% of preoperative ROM, whereas, tension-band laminoplasty (N.Tsuzuki et al. Int Orthop1996;20:275–84), which preserved SLC, maintained cervical alignment with loss of ROM by 20–40% of preoperative ROM, showing a better postoperative neck-function than that of other laminoplasties. However, about 70% of patients complained of some discomforts of the posterior neck even with good neck movements.

To obtain optimal postoperative neurological recovery, the timing of decompression was a key issue. Japanese Orthopaedic Association (JOA) score for cervical myelopathy (normal = 17 points) was used for neurological evaluation. One hundred and nine patients who underwent tension-band laminoplasty, were grouped into 3 groups according to preoperative JOA scores: group A with JOA score above 14 (10 patients), group B with JOA score between 11 and 13 (48 patients), and group C with JOA score below 10 (51 patients). Mean pre-/post- JOA scores and ratios of patients with postoperative JOA score above 16 for each group were as follows: 1

0.4/14.1, 34% for total patients, 14.6/16.5, 80% for group A, 11.9/14.8, 40% for group B, and 8.2/12.9, 20% for group C. There was a statistical difference among three groups.

It was concluded that decompression at the early stage with JOA score above 14 using tension-band laminoplasty might provide the best outcome to CSM-patients regarding neurological improvement and postoperative neck function.

An acute phase of periprosthetic bone loss occurs following total hip arthroplasty (THA). Periprosthetic bone loss undermines implant support, may contribute to its failure, and complicates revision surgery as allograft may be required to replace lost bone. We assessed the effect of a single 90mg dose of the bisphosphonate pamidronate on early periprosthetic bone mineral density (BMD), biochemical markers of bone turnover, and clinical outcome in 47 men and women undergoing hybrid THA in a randomised, double-blinded, placebo-controlled trial.

The mean (± 95% CI) differences in BMD (area under BMD change.time curve) between those receiving pamidronate and those receiving placebo was 0.91(± 0.51) g.weeks/cm² for the proximal femur (P=0.002), and 0.80 (±0.60) g.weeks/cm² for the pelvis (P=0.009). Patients in the pamidronate group had suppression of all biochemical markers of bone turnover compared to placebo (P< 0.05), except for urinary free deoxypyridinoline. Both treatment groups experienced similar improvement in Harris hip and SF-36 UK outcome scores. The frequency of adverse events was similar in each treatment group (placebo 7/24, pamidronate 8/23, P> 0.05).

Acute periprosthetic bone loss following THA is due to a transient increase in bone turnover. A single dose infusion of pamidronate in the early post-operative period significantly reduces this bone loss, and is well tolerated.

The results of 278 consecutive primary total hip arthroplasties performed with bone grafting for ace-tabular bone deficiencies were reviewed at an average of 9.0 years (range, 5–23) after surgery. All patients had underlying developmental dysplasia of the hip. For all hips, the grafts used were from the patients’ own resected femoral heads. All but three grafts were screwed to the supero-lateral aspect of the acetabular roof, the exceptions being grafts without internal fixation. Kaplan-Meier survivorship analysis predicted a rate of survival of the acetabular component at 10 years of 97% (95% confidence interval (CI), 94–100%) with revision for aseptic loosening as the endpoint, and of 82% (95% CI, 76–89%), when radiological loosening was used. Trabecular reorientation, as an indicator of graft incorporation, was seen in 89% of the joints between 1.5 and 5 years (mean 3 years), and delayed up to 7 years. Parametric survivorship analysis using the Cox proportional-hazards model indicated that trochanteric non-union, lateral placement of the socket, and delayed trabecular re-orientation of the bone graft, were risk factors for loosening of the acetabular component. Autogenous acetabular bone grafting will be of value for long-term success and has good potential for additional improvement of the results, provided these three risk factors are reduced. In order to promote the trabecular reorientation, we have gradually improved the surgical technique including sizing of bone graft and adaptation technique. By these alterations of the surgical technique, trabecular reorientation of the 51 joints operated after 1993 was completed by 4 years after surgery.

To establish whether there were features present on the initial post-operative radiographs of total hip replacements (THR) predictive of aseptic loosening.

Our data was derived from the Trent Regional Arthroplasty Study (TRAS) which is the only hip register of its kind in the country. The TRAS commenced in 1990 and has recorded clinical and operative details of all THRs in the region.

Our current study was concerned with a cohort of grossly loose THRs, identified from the five-year follow up of those patients who had undergone THR in 1990. Our cohort are those which failed specifically due to aseptic loosening and comprises those revised or listed for revision as well as a number of previously undiagnosed cases.

The post-operative radiographs were analysed, recording the following: (1) number, width and location (Gruen zone) of radiolucencies at both cement-bone and cement-prosthesis interfaces; (2) presence of stem-cortex contact; (3) width of the cement mantle in each Gruen zone; and (4) Barrack cementation grade.

Occasionally, if the initial post-operative radiograph was of poor quality, then further information was gained from the next available ones (usually at six weeks) to improve accuracy.

Comparisons were made with 60 control hips randomly generated from the same 1990 cohort but which had not failed.

Chi-squared tests were used to test the probability of obtaining the observed data by chance and odds ratios were calculated to describe relative risk of failure for different risk factors.

Hips with inadequate cementation grades (C and D) had a 9.5 times greater risk of failure compared to those with adequate cementation grades (A and B) [p< 0.0001].

We have demonstrated that the grade of cementation has a major effect on the probability of failure. This emphasises the importance of good cementing, which is particularly relevant in this era of clinical governance where there is greater accountability on the surgeon for adequate performance.

Total hip arthroplasty surgery may be associated with substantial loss of blood often necessitating blood transfusion.

The risks associated with blood transfusions are widely known. Haemostatic drugs have been tried in the past to try and reduce this, and there has been renewed interest in these recently, in particular Aprotinin (Bayer).

Aprotinin is a serine protease inhibitor, which has been shown to reduce blood loss in cardiac surgery by up to eighty percent.

The aim of our study was to investigate whether or not high dose Aprotinin can reduce blood loss and transfusion rates in patients’ undergoing total hip arthroplasty.

This was a randomised double blind controlled clinical trial, where 50 patients were randomised to receive either Aprotinin (2 x 106 KIU followed by an infusion of 5 x 105 KIU/hr), or an equivalent volume of normal saline.

Blood loss and transfusion rates were measured as well as the incidence of deep vein thrombosis.

There was a significant reduction in total blood loss seen in the Aprotinin group, median 817±350, when compared to the control group, median 1191±386. This translates to a 31% reduction in blood loss.

DVT and transfusion rates were not significantly different between the two groups.

There was no complications or deaths seen in the Aprotinin group.

The use of high dose Aprotinin results in a reduction in blood loss in total hip arthroplasty. It has been proved to reduce blood loss in cardiac surgery, and although papers have shown it can reduce blood loss in orthopaedic surgery, its’ use should not as yet be routine.

Further work is required to investigate the possibility of a future role for Aprotinin in orthopaedic surgery, as well as its’ mode of action. Until then more established methods of blood conservation should be used.

The Charnley total hip replacement has had favourable long-term survival results. On the strength of these results orthopaedic companies have introduced “Charnley Copies” incorporating identical design parameters.

The objective of the study was to determine whether the acetabular cups provided as DePuy Charnley copies by different manufacturers are identical with regards to their geometry. To analyze how any differences present may affect the motion characteristics of the arthroplasty.

A jig was designed which allowed the measurements of: i) range of movement free from impingement, ii) the arc of movement during which the femoral neck is impinging on the cup, iii) point of subluxation and dislocation of the femoral head from the cup. The cups obtained for analysis where the Standard and Long Posterior Wall models of the DePuy Charnley, Aesculap ALFA, Corin Cenator and Avatar LFA. The Aesculap Plasma Symmetrical and Asymmetrical were analyzed for comparison.

The Alfa has a greater free range of movement compared to the Charnley cup and the other copies. The Charnley cup, the Cenator and the LFA differed in their pattern of impingement. The Alfa had the earliest point of dislocation. Long Posterior Wall: The Avatar had the greatest free ROM. The Charnley and the Alfa dislocated in an anterior direction latest. The Avatar and Cenator dislocated latest in the posterior direction. Plasma Cup: Compared to the Charnley and its copies its free range of movement was greater, it had only one point of impingement and impinged through the smallest arc before dislocating. It did, however, dislocate easiest.

Charnley copies are not identical. Differences in geometry exist and these alter important motion characteristics. Long term outcome may be affected. Surgeons should be aware of these differences when choosing implants.

To clarify the short-term results of conservative treatment for symptomatic full-thickness tears of the rotator cuff.

Between September 1996 and August 1999, 107 shoulders of 105 patients were diagnosed as full-thickness tears of the rotator cuff by MRI or arthrography at our institute. All patients were treated conservatively and only 3 shoulders underwent surgery because of persistent pain after 6 months of conservative treatment. Among 104 shoulders treated conservatively for more than 12 months, 102 shoulders of 100 patients were followed up with an average follow-up period of 33 months. Two patients were excluded: one had died and the other had been lost at the time of follow up. Among 102 shoulders, 56 shoulders of 56 patients were assessed by direct examination, and 44 shoulders of 46 patients were interviewed by telephone. There were 54 males and 46 females with an average of 64 years (44–80). The Shoulder Functional Evaluation by the Japanese Orthopaedic Association (JOA score) was used for assessment (full score = 75 points)

The overall JOA score improved significantly from 41.3 points (initial) to 63.5 points (follow-up) (p< .01). Satisfactory results (> - 60 points) were obtained in 71%. The pain score (full score = 30 points) improved from 8.3 points (initial) to 24.7 points (follow-up) (p< .01). At follow-up, 49% had no pain and 88% did not need any medication. The range of motion, abduction strength, and activities of daily living improved significantly (p< .01). Angle of external rotation at initial examination was positively correlated with the JOA score at follow-up (r=0.373, p> .01).

Short-term outcome of conservative treatment for symptomatic full-thickness tears of the rotator cuff was satisfactory in 71% of the patients.

A powered, randomised control trial was instigated to evaluate the advantages of subacromial injection of Methylprednisolone over conservative treatment in the management of partial rotator cuff injuries of the shoulder.

Consecutive patients with possible partial rotator cuff tears were reviewed at 1 week. Inclusion criteria for a diagnosis of partial rotator cuff tear included; traumatic mechanism, greater tuberosity tenderness, painful arc, and complete resolution of disability post-Bupivicaine block. Exclusion criteria included; age < 16 years, chronic shoulder disease, acromioclavicular tenderness, and abnormal shoulder radiograph. Patients were randomly allocated to receive either 1 immediate subacromial injection of 40mg Methylprednisolone (group S) or no injection (group N). Initial outcomes measured were; visual analogue pain score (0–10) and active abduction (nearest 5°), repeated at 3, 6, and 12 weeks. All patients were instructed in analgesia usage and given identical shoulder exercises.

Of 279 patients reviewed over 3 years, 90 met the inclusion criteria (6/90 patients were lost to follow-up). 50 patients were randomised to group S, 40 to group N. Mean pain score improvement at 12 weeks was comparable (S=4.95, N=4.44) (p> 0.1, CI=0.16–0.86). In patients aged > 40 years group S had significantly higher mean improvement in abduction at completion (64.28°) compared to group N (34.63°) (p< 0.02, CI 1.29–58.01). Conversely in patients aged < 40 years group S had lower mean improvements in abduction (40.55°) compared to group N (77.73°), though this was not statistically significant (p=0.1, CI 2.06–72.29)

Methylprednisolone injection is more efficacious than conservative treatment alone in some patients. This benefit appears age-dependent and consequently such treatment should be reserved for patients aged > 40 years.

This study was performed to assess the relationship between patients’ pre-operative symptoms and their expectations at the time of revision hip arthroplasty. The WOMAC (Western Ontario and McMaster Osteoarthritis Index) scale for osteoarthritis of the hip and the Short Form 36 (SF-36) general health status scale have both been validated for the assessment of the outcome of hip arthroplasty. We prospectively assessed 60 patients using these scales as well as the “expectation WOMAC” that asked the patients to estimate how they expected to feel 6 months after revision hip replacement. All the questions were completed prior to informed consent, and were scored form 1 to 5 with increasing severity with a Likert scale. The maximum possible scores for pain, stiffness and difficulty with physical activity were therefore 25, 10 and 85 respectively.

The mean preoperative WOMAC score for pain was 13.4 (CI 12.2.-14.6), for stiffness 5.9 (CI 5.6-6.2) and for physical activity 50.9 (CI 47.2-54.6) The mean expectation WOMAC scores for these modalities were 7.4 (CI 6.2-8.6), 3.5 (CI 3.0-4.0) and 28.1 (CI 24.0-32.2.) respectively. Although there was a wide spread of expectations, we were unable to find any significant correlation between the patients’ preoperative pain and The abstracts were prepared by Mr Simon Donell. Correspondence should be addressed to him at the Department of Orthopaedics, Norfolk & Norwich Hospital, Level 4, Centre Block, Colney Lane, Norwich NR4 7UY, United Kingdom. stiffness levels and their expectations for pain and stiffness after revision hip arthroplasty. There was however a statistical association between their preoperative difficulty with physical activity and their expectations for physical activity (r=0.38; p=0.02) There was no significant correlation between the SF-36 scores and the patients’ expectations.

The expectations of patients awaiting revision hip replacements are high, and do not appear to be closely related to their level of pre-operative disability. Even patients with severe symptoms have high expectations that in some cases may be unrealistic. The use of the “expectation WOMAC” may help us to identify such patients, and to improve patient education and satisfaction.

A modified Kessel trans-acromial approach has been utilised in our Unit for decompression and repair of associated rotator cuff tear for all advanced impingement syndrome (Stage III). This preliminary report aims to review our results, and to assess the complications of this approach.

From 1996 to 1999, 22 consecutive patients who were treated surgically using a Trans-acromial approach for advanced impingement syndrome, were reviewed. The diagnosis of impingement syndrome was based on history, physical examination and Lignocaine impingement test, with either an ultrasound scan, arthrogram, or MRI. The modified trans-acromial approach was used involving splitting and raising a periosteal soft tissue flap over the acromion, followed by splitting the acromion in the coronal plane just behind the acromioclavicular joint, this allowed an extensive exposure of the rotator cuff and easy undercutting of the acromion.

20 patients were interviewed and examined specifically for this study, for an average follow up of 17 months. The other two patients were interviewed by telephone. The following parameters were studied: 1) functional assessment:[Constant’s Scoring system, and the UCLA Shoulder rating Scale. 2) Pain relief. 3) Patient satisfaction. 5) Return to preoperative activity. 6) Complication. The results were satisfactory in 17 patients (77%), and unsatisfactory in 5 pt (23%), one of which had cervical spondolysis, and two had new bony formation in the subacromial space. Pain relief was achieved in 78%. All patients returned to their preoperative occupation apart from one. Two patients had persisting impingement and had undergone revision subacromial decompression with satisfactory results.

The modified trans-acromial approach is an acceptable alternative to open anterior acromioplasty. It offers adequate decompression of the sub-acromial space, allowing a wide exposure and excellent visualisation of the rotator cuff. This facilitates cuff repair and mobilisation, while maintaining the integrity of the deltoid muscle, which accelerates postoperative rehabilitation.

At least 10% of consultations in General Practice are for musculoskeletal problems. It would seem appropriate that the diagnosis and management of common musculoskeletal problems should form an important part of the “core” curriculum of any undergraduate medical training. Time is always short in an undergraduate teaching program and the pressures not to overload the curriculum are constant. The planned increased in student numbers is likely to stretch the ability of most teaching departments to provide a high level of undergraduate training in musculoskeletal disease.

A postal survey of the provision of undergraduate teaching in T& O was performed in the UK. All 23 medical schools in England, Scotland, Wales and Northern Ireland were. To gain further insight into non-specialist general training in T& O after qualification a survey of the Vocational Training Schemes (VTS) for General practitioners in the Northern Deanery was performed.

Ninety-one percent of Medical Schools replied. The average length of the orthopaedic attachments (all years combined) was five weeks. However, all but two programs were combined with other clinical subjects. The dilutional effect of these other subjects resulted in the average duration of the T& O attachment being reduced to 2.7 weeks (range 1.5 – 6). All the modules in orthopaedic surgery except one included trauma within the curriculum.

There are four VTSs in the Northern Deanery. All of these had schemes that included A& E but not for every trainee. No scheme had either a rheumatology or orthopaedic surgery placement, although some exposure to rheumatology occurred during attachments in general medicine.

This study shows that there is a significant discrepancy between the amount of time, within the curriculum (4%), devoted to musculoskeletal/orthopaedic teaching and the number of consultations in General Practice (10%); this discrepancy is not made up during VTS placements. In addition, such short exposure to a large subject may encourage superficial learning which medical education is specifically trying to avoid.

We hypothesise that patients are unable to recall much of the information imparted during the informed consent procedure. This may have important medico-legal consequences and increase patient anxiety. Receiving the information in a written format may improve patient recall. There have been no previous studies testing recall or information sheets for British orthopaedic patients.

We performed a randomised controlled trial of consent for total hip arthroplasty, with one group of patients receiving a written information sheet with explanation as necessary, and the control group receiving the same information verbally. The consent was obtained at a pre-operative assessment clinic approximately three weeks before admission. On admission, a questionnaire was filled in both groups of patients to assess recall.

There were no significant differences between the two groups with regard to type of arthroplasty (revision or primary), age, or days from consent to admission.

The group receiving written information performed better in the recall questionnaire. This group were pleased to have received the information sheet, there were no negative comments about the sheet. In the group who received verbal information, most expressed a desire to receive a written information sheet. One patient stated that she would rather know nothing about the operation and would have refused a sheet. We conclude that patient information sheets are an acceptable and appropriate method of imparting the necessary information for informed consent for total hip arthroplasty, and are more effective than standard verbal informed consent.

Medico-legally, the sheet could be a permanent record of what was discussed. This should prevent disputes and claims due to poor recall of the consent procedure.

In Total Knee Arthroplasty (TKA) and Total Hip Arthroplasty (THA) the total blood loss is composed of ‘visible’ blood loss from the surgical field and wound drainage, and blood loss into the tissues which is ‘hidden’. Blood management should be aimed at addressing the total blood loss.

56 TKAs and 46 THAs were prospectively studied. TKAs were performed with tourniquet. After tourniquet release, all drained blood was salvaged and significant volumes reinfused. No reinfusion was used for THAs.

The true total blood loss was calculated in the following way:

Patient Blood Volume (PBV) is: [1]

PBV = k1 x height3 + k2 x weight + k3

Therefore patient total Red Blood Cell volume (RBCv) is:

RBCv = PBV x Hct. (where Hct is Haematocrit)

Total RBCv loss = PBV x (Hct preop – Hct postop) + ml RBC transfused

The result is reconverted to Whole Blood volume.

Hidden Loss = Total Loss – Visible Loss.

In TKA, the mean total true blood loss was 1474ml. The mean hidden loss was 735ml. Therefore hidden loss is 50% of the total loss and the total true loss following TKA is twice the visible volume. In THA, the mean total true blood loss was 1629ml. The mean hidden loss was 343ml.

Thus hidden loss in THA is much smaller. (21%) Total loss is 1.3 times the visible loss. In the TKA group, comparing patients with large losses receiving reinfusion and those with small losses not receiving reinfusion, the proportion of total true loss which was hidden was the same, at 50%.

Patients with Body Mass Index (BMI) > 30 were compared with those with a BMI < 30 and no correlation was found between BMI and Hidden Loss.

Joint Replacement Surgery involves a ‘hidden’ blood loss which is not revealed and cannot be measured or reinfused in practice, but which should be taken into account when planning blood loss management. In TKA it is substantial. In THA it is much smaller and probably not of as much clinical concern. Hidden loss is no greater in the Obese patient.

Skeletal tuberculosis is an indolent disease whose diagnosis is often delayed. Evidence of pulmonary tuberculosis is present in less than 50% of cases. We present our experience from a small inner city district hospital of the difficulties managing patients with skeletal tuberculosis.

During the period 1988 to 1998 a total of 38 patients with tuberculous osteomyelitis confirmed microbiologically by tissue culture or histologically on material gained at biopsy presented to our inner city hospital serving 250 000 patients.

Two groups of patients were identified in our series. There was an acute group that tended to affect the appendicular skeleton and who responded to local treatment plus chemotherapy with restoration of normal function. In contrast the second group, who were difficult to diagnose, had axial skeleton involvement, deteriorated before treatment and had a poor outcome despite treatment. Failure of admitting medical teams to examine the axial skeleton in their confused patients led to a delay in diagnosis of skeletal tuberculosis in this second group with profound consequences.

All health professionals will be encountering skeletal tuberculosis more frequently with the recent resurgence of pulmonary tuberculosis. They may have little experience with the management of this condition and may overlook the diagnosis with consequent catastrophic results. A high index of suspicion is required for prompt diagnosis with early referral to an orthopaedic surgeon improving outcome.

Survival in the wake of hindquarter amputation and oncological treatment is improving; the hindquarter amputee population is increasing. Some amputees function well others do not.

To assess quality of life and function of hindquarter amputees.

21 amputees (10 females and 11 males) consented to take part in the study. Ethics approval was sought. Assessment was performed using postal questionnaires; SF36 for quality of life; TESS (Toronto Extremity Salvage Score) for physical function and mobility; IEFF( International Index for Erectile Function) for male sexual function; a prosthetics questionnaire to assess prosthetic use.

Mean age of the group was 55 with the mean survival of 7 years post amputation.

Quality of life results were compared to normal subjects and patients for long tern illness. Amputees had a significant reduction in quality of life concerning physical function and pain. Social function, mental health and energy levels were equivalent to patients with long term illness.

The mean TESS result was 56.9 with females having a mean score of 61.7 and male of 48. 50% of the group considered themselves as severely to completely disabled; 50% considered themselves moderately disabled. Five were in full time employment.

Six males responded to the sexual function questionnaire. Impotence was universally experienced.

Only five amputees used their prosthesis regularly. All amputees have experienced and 20 continue to experience phantom pain.

This study illustrates that hindquarter amputees have poor physical function and a low quality of life. Phantom pain is universally experienced. Male amputees experience impotence. Addressing these areas would improve the life of current and future hindquarter amputees.

The latest government targets state that by the end of 2005 the maximum waiting time for an outpatient appointment will be 3 months. These recommendations will not only increase the size of the outpatient clinics, but also the resources required thereafter. The purpose of this study was to analyse the outcome of new knee referrals to one consultant’s knee outpatient service in order to quantify the resources required to investigate and treat these patients.

All new patients attending one consultant’s knee out-patient service in the time period January 1st 1997 to December 31st 1997 were prospectively entered into a database recording patient details, source of referral and provisional diagnosis.

Eighteen months after the time period a cohort of 200 patients was randomly selected and the notes were analysed retrospectively. The number of outpatient appointment episodes (OPAs), MRI scans, physiotherapy referrals and surgical episodes generated were recorded for each patient.

Analysis of the initial database records show that a total of 662 new knee referrals were seen in 1997. 52% (341) were made up of the five most common diagnoses, these being osteoarthritis, anterior knee pain, major anterior cruciate ligament injury, medial ligament injury and medial meniscus injury.

Retrospective analysis of the 200 patient notes revealed that these patients required a total of 511 OPAs, 38 MRI scans, 178 courses of physiotherapy and 93 surgical episodes (53 elective and 40 daycase/emergency). These figures can be extrapolated to account for the total number of patients seen:

The resource implications of a new knee referral are substantial. Extra resources must accompany each new patient, otherwise, although government targets will be reached the time taken to complete each patient’s treatment will become longer. It is imperative that before an agreement is made to see new patients the resources required to manage them are in place.

To investigate the incidence of complications arising from clavicle fractures in children and the need for multiple review in fracture clinic.

Retrospective analysis of 200 children with isolated clavicle fractures. The number of clinic visits was documented along with the mechanism of injury and any complications attributable to the fracture. Plain radiographs allowed classification of the fractures both in terms of site and type of fracture.

Retrospective review failed to provide any evidence of long term complications from isolated clavicle fractures. Two patients complained of a non-specific tingling in the arm which had settled within 2 weeks. No intervention other than rest in a broad arm sling was deemed necessary in any of the 200 children. Despite this, the average number of clinic appointments was 2.8.

In the prospective study there were no complications arising from an isolated clavicle fracture. Two patients returned (one at 6 weeks and one at 12 weeks) with concerns about the cosmetic appearance of the fracture site - both patients were reassured and discharged. All patients were satisfied with the cosmetic appearance and function of their shoulder when reviewed at a mean of 7.3 months post injury (range 6–10 months). All patients and/or guardians were satisfied with the patient information sheet.

Isolated clavicle fractures in children are rarely complicated by injuries such as skin necrosis or a neuro-vascular deficit. Despite this, children are commonly reviewed many times by juniors in a busy fracture clinic. We suggest that such review is unnecessary and that uncomplicated fractures may be safely discharged with a patient information sheet after the first clinic appointment.

The displaced intracapsular fracture in the elderly has frequently been termed the ‘unsolved’ fracture because of the debate as whether the femoral head should be preserved or replaced. To answer this question 413 patients aged over 70 years with a displaced intracapsular fracture were entered into a prospective randomised trial, to treatment with either an uncemented Austin Moore hemiarthroplasty or reduction and fixation with three cancellous screws. Pathological fractures, Paget’s disease and rheumatoid arthritis patients were excluded. Analysis of pre-operative characteristics of patients showed there was no significant difference between the two groups. Mean follow-up of surviving patients was 827 days.

Internal fixation resulted in a reduced mean operative time (22 versus 47 minutes), operative blood loss (23ml versus 171mls) and transfusion requirements. There was no significant differences in the incidence of post-operative complications between treatment other than and increased risk of wound sepsis for arthroplasty (4/207 versus 0/206 deep wound infections). There was a consistent tendency to a marginally lower mortality following internal fixation (15.5% versus 12.7% at 90 days).

Six patients in the arthroplasty group required revision, four for loosening, one for sepsis and one for fracture around the implant. Non-union occurred in 64(31%) of those treated by internal fixation. Most of these patients had conversion to arthroplasty. Other complications of internal fixation requiring secondary operations were avascular necrosis (4 cases), fracture below implant (1 cases) and removal for painful screw heads (7 cases). Functional assessment of the survivors at one year from injury showed no significant difference between the two groups for pain or change in mobility.

These results indicate that arthroplasty for displaced intracapsular fractures in the elderly is associated with a reduced re-operation rate but at the expense of a marginally increased mortality.

A prospective study of 142 consecutive patients admitted with fracture of the neck of femur was performed. 42 patients were operated within 24 hours of time of fracture (group 1), 46 within 24 to 48 hours (group 2) and 47 more than 48 hours later (group 3). Three patients were treated conservatively and in four patients the exact time of fracture was not known.

The reason for delay of the operation was lack of theatre space in the majority of cases (64 patients). Medical problems accounted for delay in only 10 patients.Seven patients out of 42 in group 1 died within four month (16.7%), compared to 11 of 46 in group 2 (23.9%), and 6 out of 47 in group 3 (12.8%). This difference was not statistically significant.

There was no significant difference in requirement for pre- and postoperative blood transfusion between the three groups. No patient operated within 24 hours developed pressure sores. Three patients in group 2, and six patients in group 3 developed pressure sores. Chest infections occurred in three patients in group 2, and in three patients in group 3. None of the patients operated on within 24 hours developed a chest infection, wound infection or urinary tract infection. Two patients who had a Girdlestone procedure for deep infection were operated more than 48 hours after the fracture. One patient requiring drainage for wound infection had the operation 47 hours after the fracture.There were no superficial or deep wound infections, pressure sores, or chest infections if operated on within 24 hours of fracture. There was no difference in the requirement for blood transfusion. Patients operated within 24 to 48 hours of fracture had the highest mortality, although this was not statistically significant.

The perineal traction post has been reported to cause pressure sores, skin necrosis, and pudendal nerve palsy. Tissue pressures of 70 mm Hg applied for two hours have been shown to result in microscopic tissue change whilst pressures of 1.4 kg/cm² for 90 minutes produced severe or complete nerve conduction block.

To demonstrate perineal traction post interface pressures. To assess effect of padding type on these pressures.

Healthy volunteers were positioned supine on the traction table with the right lower limb supported in flexion and abduction. Longitudinal traction of 40kg was applied to the left lower limb through the boot. Pressures were measured using a pressure pad consisting of individual calibrated inch square pressure cells. The pad was placed around the traction post. Five different types of padding were used on a standard traction post. These were: gamgee, small gel pad, 10cm gel bolster, 10cm soft foam roll and 10cm hard foam roll. With each device, the leg was positioned in neutral, internal rotation, external rotation and adduction. Pressure readings and pain scores were recorded with each manoeuvre.

Maximum pressures were experienced with the gamgee wrap. All subjects noted their highest pain score here. Peak pressures of 100 mm Hg were demonstrated over the ischial tuberosity and adductor tendons. The larger padding devices resulted in significantly lower pressures. Of the different positions, adduction was that which resulted in highest pressures and pain scores, though this was not significant.

The highest pressures exceeded the 70 mm Hg limit known to cause tissue damage. These pressures can be reduced with alteration of the padding. In all procedures it is important to pad the post carefully and use adducted positions for as short a time as possible.

In 1991 15% of the UK population that travelled abroad required medical assistance. We have been treating more patients with lower limb injuries requiring repatriation via aircraft. Recommendations from Airlines were unavailable. 357 Consultants replied to a questionnaire about transportation of patients with a lower limb injury wearing a plaster cast. There was no consensus on safe transportation of these patients. No scientific data is available on the dynamics of transportation of patients with lower limb trauma. In order to assess the safest method of transportation an experiment was conducted. Ethical committee approval was granted. Five volunteers wearing above leg plaster casts were placed in a decompression chamber. The effects on anterior compartment pressures, Doppler venous return, ambient pressure between plaster and skin were assessed in different positions with and without plasters being split. In the normal population we have shown a trebling of intracompartmental pressures from an average of under 10mmHg to 30mmHg. Intracompartmental pressures are more raised with 90 degrees of hip flexion rather than 45 degrees. We recommend patients be transferred with their legs at 45 degrees to the ground with a split plaster cast.

Following fixation of proximal femoral fractures in the elderly the operating surgeon may request that the patient be mobilised partially weight bearing on the injured limb. This instruction is most likely if the bone quality is very poor or the fracture pattern unstable, despite evidence that full weight bearing does not affect outcome.

98 elderly patients with proximal femoral fractures treated by either hip screw device, cannulated screws or hemiarthroplasty, who were previously independently mobile, have been followed prospectively to determine their ability to comply with partial weight bearing instructions.

A specially designed capacitance foot pressure device was used to determine percentage body weight transferred through the injured limb on mobilising under physiotherapy instruction over 5 days, and factors thought to be predictive of success in partially weight bearing were measured using simple ward tests.

14 patients failed to mobilise independently prior to discharge from hospital and were excluded from further analysis. Of the remaining 84 patients only 24 (28%) successfully managed to partially weight bear 30-50% of their body weight on the injured limb. Only six of those who were unable to partially weight bear on starting to walk after surgery had learnt to do so by the fifth day. Factors indicating success or failure were mental test score, grip strength and straight leg raise on the unaffected side.

This study has shown that the majority of elderly hip fracture patients are unable to partially weight bear but, if required, success can be predicted by a few simple ward tests.

It is hoped that this information will lead to the more appropriate use of inpatient physiotherapy resources.

The principle of the sliding hip screw is to provide a controlled collapse at the fracture site. It is during the screw insertion that clockwise rotational torque is imparted to the head and neck

In right-sided fractures the screw causes the head fragment to rotate clockwise leading to apposition or flexed position of the fracture site. In Left sided fractures the clockwise rotation leads to the head and neck fragment into extension of the fracture site leading to a potentially unstable construct.

All intertrochanteric fractures treated over a 12-month period were assessed. 75 fractures were included in the study. The fractures were classified according to Tronzo’s classification (Grades I & II – stable; Grades III & IV – unstable). Intraoperative and postoperative films were assessed for rotational abnormalities in the form of an anterior spike of the proximal fragment in left-sided fractures and a flexed position of reduction in right-sided fractures.

There were 39 Left sided fractures and 36 Right sided fractures.

A rotational abnormality was seen in 11 Left sided fractures compared with none on the right side. All 11 abnormalities were seen in Grade III and IV fractures (2 and 9 respectively). Analysis of results using the Chi-Square test revealed a significant difference (p < 0.001). 3 out the 11 fractures with rotational anterior spike had an implant cut out which needed revision surgery.

Compared to stable fractures, the accuracy of reduction determines the final stability in unstable fractures. In these fractures the rotational torque imparted to the proximal head and neck fragment can cause loss of reduction leading to potential failures of fixation. This appears to be greater in left sided fractures where the rotational torque causes the anterior spike which when not butressed inferiorly and medially can lead to a state where the implant cannot control the shear forces at the fracture site. This can then lead to failure of fixation.

In right-sided fractures the rotational torque often causes compression of the head and neck fragment into the distal fragment with the creation of an infero- medial butress.

The methods of overcoming this problem are with modifications in the technique. Untwisting the last few threads of the screw after insertion could reduce the anterior spike. The application of digital pressure along the anterior neck or the application of a reduction clamp at screw insertion provides counter rotation.

The results of this study confirm that the problem of torque at the fracture site is not of considerable importance in stable fractures but is significantly so in unstable left sided fractures. This results in a greater predisposition for potential failure of fixation

A randomised, prospective trial comparing the percutaneous compression plate (PCCP) and the classic hip screw was performed for intertrochanteric fractures of the femur in 108 patients. The PCCP offers the ability to stabilise fractures with a minimal exposure and periosteal stripping thus preserving soft tissue cover.

Over a 19-month period all patients with extra-capsular fractures apart from subtrochanteric and pathologic fractures were included. They were classified as per Evans classification.

The patient’s pre-operative haemoglobin, premorbid mobility, medical and mental status were noted. The duration of the procedure, screening time, blood loss and any technical difficulty encountered along with the post-operative haemoglobin, drainage and transfusion requirements, as well as the length of stay in the orthopaedic unit and total length of stay in the hospital were recorded. Results were analysed using the Chi-square test and Student’s test.

The operating time was significantly longer in the PCCP group (mean 59vs49mins,P< 0.05). There was no significant difference between the two groups with regard to the other parameters measured.

There was no difference in the failure rate (2 cut-outs in the CHS group and one screw back-out in the PCCP.) With the device being of fixed single angled design it proved to be unsuitable for 3 patients.

The PCCP would appear to be as good as the more conventional device though it does not confer the perceived advantages of decreased duration of stay or significant reduction in transfusion requirement which are associated with other percutaneous procedures. The device is a single fixed angle one and is therefore not universally applicable to all patients.